"Well... Just relax... And leave it to me!"
Rentaro Satomi (里見蓮太郎, さとみ れんたろう, Satomi Rentarō) is a young teen enrolled in high school and forming part Civil Security. He is a Promoter who is partnered with Initiator Enju Aihara. He is the protagonist of Black Bullet.
Rentaro Satomi is a young teen of small frame and messy dark blue hair, with slightly slanted eyes and blue irises. His dark blue hair partially covers the whole of his forehead; reaching down below his eyes with a parted set of bangs untidily forming. Rentaro possesses thick sideburns connected to his hair which hang loose around his cheekbones on either side. Further; several strands of his unkempt hair, having gaps in several locations, arch around his thin eyebrows and hover on top of his thick eyelashes. His nose serves as roof to thin lips and a small jawline. He has small ears and normal-sized feet. Despite his profession, Rentaro shows no scars in any visible part of his body.
Rentaro dons a black suit covering his body entirely. The jacket, which he leaves open with solely one button connecting the two sides in the center, displays a much lighter color in the inside; resembling the color light blue. On the right side, there's a strap of the same light blue color linearly craved from the collar of the jacket to the bottom. Additionally, the inner collar displays thin black lines similar to the ones on the strap. Underneath the jacket, there is a notable white shirt with a large turtle neck held together by a blue tie around his neck. Around his wrist, Rentaro keeps the large blue cuff, with a small white line circling around the middle, folded accordingly. The shirt underneath the jacket is kept in messy standards, as one of the sides is inside the pants whilst the other is left out in the open. Rentaro's lower body is sheltered by a pair of pants that are held around his waist by a blue belt with a small white line encompassing around the center; serving as a form of adornment. The back of the black pants show two pockets, each serving as inventory for his wallet containing his Civil Security license. He travels around in high black shoes that have a much lighter color at the bottom.
Rentaro shows, however, anger when spoken to of his dead parents. When Kisara inquisitively questions his ambition to "find" them, he burst out into a cry of vivid fury and abruptly leaves her without saying another word. He sometimes portrays lack of confidence when it comes to his skills as a fighter, even to the point of dropping a mission given to him by the agency. Even so, when faced with threats greater than him, Rentaro retains his calm nature and gains the strength he needs to protect the ones he cares for. He also cares deeply for Kisara and have shown some feelings toward her. 
At the age of six, Rentaro's parents passed away, leaving him at the care of Kikunojou Tendo, who wantonly welcomed him into the Tendo family with open arms. However, as tears dropped down his face, Rentaro held a burned charcoal in his hands as he ran from the funeral of both his parents telling himself that his parents were in fact alive and that he will find them. When the Cursed Children were born into the world, women would give birth by a river to quickly drown them and relieve themselves from the burden; Rentaro bared witness to this as a kid as he walked past a river. When Gastrea first began, Rentaro was attacked and mortally wounded, but healed by several doctors after he signed a contract to live. During his first days as a Civil Security member, when Rentaro first met Enju, the former was attacked by the latter instantaneously. Later on however, the two developed a strong bond.
Civil Security arc
Whilst scratching the back of his head, Rentaro is asked by Tadashima if he is truly the Civil Security Corporation member they sent as reinforcement, to which he responds affirmatively and states that if he does not believe him he will just return home. However, he is then questioned by Tadashima to show him his license, which he does, and quickly receives it back as the latter confirms his statement. Commencing the operation, Tadashima informs Rentaro that on the second floor, where the accident happened, the roof was leaking blood. Quietly standing behind the man, Rentaro is told that it's thanks to him that they will be able to investigate the crime scene further, aiding him to enter the building. Along the way, he is asked what happened to his Initiator, causing him to shudder and remember said person fall from his bike on the way to his current location. Afterwards, when they arrive to the room, Tadashima confronts one of his men for entering the room without permission, but Rentaro simply shakes it off and, taking a hold of Tadashima's shoulder, orders him to stand to the side as he will enter the room.
Readying his gun, Rentaro bashes into the door, successfully entering the room and inspecting his surroundings. Finding nothing, he stands still until hearing a voice. He turns around and sees two men terribly beaten and a masked man standing in front of them. The masked man looks at Rentaro and tells him that he is late, and confirms that he was the one who killed the men behind him. Rentaro rushes towards him and attacks, but is met by a similar attack that blocks his and sends him flying backwards. As they fight, the masked man holds the upper hand. When suddenly, he receives a call, and picking up the phone, shoots the men entering the room wanting revenge. Enraged, Rentaro picks up his speed and hits the masked man in the face, but proves futile nonetheless as the latter simply hangs his phone and takes his leave after asking for Rentaro's name.
Befuddled, Rentaro is brought out of his train of thought when Tadashima enters the room and shakes him. He quickly orders them to search for the source of the infection, which they do but come out empty handed at the end. Rentaro then looks at a photo near him, asking Tadashima if the man lived alone, to which he responds positively; a divorced. Searching the area, he comes close to a puddle of blood and ponders what could have happened. Analyzing the situation, Rentaro tells Tadashima to give out the order to evacuate the civilians due to the infected and the infection being out in the wild. Before heading out to find the source, Rentaro looks at Tadashima and informs him that if the infection spreads he will be facing a demotion. The two leave the building and look for the Gastrea.
As they walk around, they see traces of blood, and quickly locate the Gastrea. Stating the Gastrea's type, Rentaro watches as Tadashima shoots at it, having no effect. Seconds later, Rentaro saves Tadashima from an incoming attack. After explaining that regular bullets have no harm on the Gastrea, Rentaro takes his gun from him and gets ready to fight the Gastrea, telling him to leave it to him. Rentaro shoots the Gastrea multiple times, but, unlike Tadashima's attacks, inflicting harm upon it. However, as he stops his attacks and moves in to inspect it, he is almost ambushed if not for a young girl stepping in and killing the Gastrea with a kick. Whilst standing behind her, Rentaro hears her state her name and inform Tadashima that she is Rentaro's Initiator: Enju Aihara.
Rentaro is informed by Enju what happened 10 minutes prior to his arrival, and then turns to look at Tadashima to apologize for being careless against a low level enemy. However, he states that it's fine, and asks Rentaro to explain the reason why his bullets were working in comparison to his. Rentaro takes out a bullet and shows it to him, calling it "Black Bullet - made from Varanium", which can cause wounds to Gastrea that they won't be able to recover from. He then proceeds to explain the various ways in which Varanium can be used, shocking Tadashima. Quickly asking a new question related to Enju's flaring eyes, he is met by the response of she being an Initiator.
Moments later, Rentaro is told by Enju that, when she was not around, he did very well against a Gastrea, and is kissed on the lips by the young girl. Though, angry, she kicks him in the groin for leaving her behind like he did, causing him to fall on the ground in pain. On the ground, Rentaro looks at Enju and notices the wound on her back, but is relieved when she heals it with her extraordinary recovery speed. Rentaro then explains to the confused Tadashima that despite their superior abilities, Initiators have the hearts of humans, and it is the reason why he will show her the way. Called by Enju, he is told of the man's dying words before turning into a Gastrea, looking at the dead Gastrea in sorrow.
Rentaro gets ready to leave as he parts ways with Tadashima when Enju questions if they can still make it to the limited sale, causing him to take a piece of paper out of his pocket and being to run away as he tells Tadashima that one bag of beam sprouts is only 6 yen; leaving the latter ultimately shocked. Along the way, Rentaro and Enju see the Monoliths that protect the area around, amazed by their height. He explains to Enju that probably the whole world is protected by Monoliths, which are made from Varanium. Reaching back to the company, Rentaro is confronted by an angry boss, who begins to chase him around and, after getting tired, tells him not to call her by her name whilst at work, instead; president. Sitting down, Rentaro is confronted by Kisara for forgetting the reward and not telling her about the limited sale. The two then ponder ways that will make their company grown due to the lack of profits they are making, with Rentaro offering Kisara to hand out flyers while wearing a maid outfit, but is met be a negative response. Quickly changing the topic to work, Rentaro is told by Kisara that the original Gastrea that infected the man is yet be located, and currently there haven't been any witness reports; leaving Rentaro horrified.
The Cursed Children arc
Rentaro speaks to Kisara and believes that it is impossible to think that there is not even one witness report on the source of the infection, only to be told by Kisara that there is one, as she looks at him. He asks her for the government's reasons for not sounding the alarm, but Kisara explains that the government would not use compulsory measures such as the evacuation alarm, and tells him that it's up to Civil Security to find the original Gastrea. Rentaro begs to differ, and states that he will seek the opinion of an expert, namely his sensei; receiving encouragement from Kisara. The two get ready to leave when Rentaro asks Kisara if she would like for him to escort her home, but is told that she will be headed elsewhere first. Kisara asks him if Enju had already went home, to which he responds affirmatively and is soon asked by Kisara to reveal his goal; asking if it's to find Enju's parents noting as he gave up on finding his a long time ago. However, he feels uncomfortable and, after telling her to stay out of his business, storms out whilst calling her annoying.
Outside, Rentaro seats and remembers his parents' funeral, thinking to himself that he will apologize to Kisara the next day as he walks away. Reaching a hospital and an intricate door, he is met by a creepy figure in the other side, who turns out to be his sensei holding a statue. He watches as she personifies the status, and then talks to her about the Gastrea. Sumire approaches him yells at him for not killing it more carefully, following to question him if he has already lost hope in the world in a comic way. She takes a seat and tells Rentaro that if he will always be the way he is, Kisara will dump him, causing him to blush and remind her that she was inaugurated into the secrets of the "Tendo Sword Style" and that a beginner of the Tendo Combat Style like himself would stand no chance at victory when in a fight. Rentaro hears as Sumire solely states that she knows, but also reminds him that she used to protect him when they were young, angering him.
The two commence to talk about Gastrea and their superior abilities, with Sumire claiming that the original Gastrea managed to escape using something she calls Evolutionary Jump. Rentaro contradicts her and believes it was able to camouflage itself. Before they can continue, Rentaro brings up Enju's name as he claims that they will protect the Tokyo Area from the Gastrea, when suddenly Sumire begins to speak about the Cursed Children and how they were born to fight the Gastrea. Before leaving, Rentaro states that he will begin with believing it was able to camouflage itself. Reaching back home and cooking for both him and Enju, who claims it is delicious, he looks at the time and informs Enju that it's time for her shots. He grabs the an erosion resistance shot and begins to insert the liquid in her. Rentaro recalls the time women would have give birth by rivers to drown their kids if they were born with Gastrea blood, he as well remembers the time he met Enju; attacked by the latter due to her distrust for humans. He finishes giving her the shot, and soon brings a portable bed out to the floor, ignoring Enju's statement about her heart being ready, annoying her. The next morning, Rentaro wakes up with injuries from Enju's anger, and states that he does not want to go to school; claiming that he will use leaving his bike near the accident scene as an excuse. As he walks out the bathroom he sees an energetic Enju bring the news of the landlady lending them her bike. Before they leave their house to go to school, the news calls for their attention as Tokyo's protector, Seitenshi, appears.
Rentaro watches the news closely as Seitenshi and Kikunojyo Tendo, standing beside her, approach a balcony. Enju looks at Kikunojyo and immediately turns to Rentaro, who dismisses said man and looks at the time; rushing out the house as he turns the television off. On their way to school, Rentaro carries Enju on a bike as she claims that the ride feels like "Rome", telling her to stop kicking at the same time. Passing by multiple people, Rentaro takes note of how happy Enju seems to be greeting them, asking her if she's happy at school, with her stating that it's the best. Dropping her off, he reminds her to keep the kids at school from knowing that she is one of the Cursed Children. Enju, looking at Rentaro in a serious manner, confirms that she is already aware of the fact and receives and apology from the latter. Momentarily, her friend, Mai, comes along and walks to class with Enju. Rentaro then grabs the bike and heads to his school.
Once there and after it's time for lunch, he receives a call from Kisara, but ignores until said person comes to his class and asks him for his motives for not picking up. She informs him that they were summoned by the Ministry of Defense, prompting Rentaro to ask for their reasons, with Kisara bluntly telling him that their current location is not the place to be exposing said information. As they leave the room, he is asked by Kisara for his IP Rank, and followed by asking him for an estimate of Enju's IP if she were to switch partners; claiming that if she were with another Promoter her IP would be 1000 or lower. Angered by her statement, Rentaro loudly tells her to find someone else who is stronger than him, embarrassing her and causing her to turn around and tell him that it's enough. When suddenly, he hears her stomach growling; ordering him to give her his food seconds later.
On the train, Rentaro, who has a sleeping Kisara on his shoulders, hears her speaking in her sleep about getting revenge on the Tendo, hugging her afterwards. Once they arrive to the place, they talk among themselves about the original Gastrea until being welcomed by a young girl. Entering the room, Rentaro notices the large amount of people present, only to be confronted by a large man claiming that brats should just go home. Rentaro solely stands there and asks for his company's name, but is met by a headbutt that sends him back. Picking himself up, he gets ready to fight the man.
Rentaro is called irritating, but returns the insult to the man assaulting him. As soon as he grabs his gun, the tall figures asks him for his "tool's" whereabouts; leading him to ponder his statement. The man then confirms that by "tool" he is speaking of the Initiator, which angers Rentaro and forces him to contradict his statement about them being tools. However, before they can continue their small scuffle, Kisara stops Rentaro whilst a man stop the hefty man. Rentaro then speaks to Kisara, who informs him of Shougen Ikuma's IP rank, shocking him. Watching as the man walks away, he takes note of the girl standing beside him, wondering if she is his Initiator.
Afterwards, when two men enter the room and commence the meeting by turning on a live streaming of Seitenshi, Rentaro looks at Kisara, who is glaring at her grandfather, Kikunojyo, and remembers that he is her sworn target. Rentaro hears as Seitenshi reveals the mission of retrieving a case, and watches as Kisara questions her about the contents of the case; but in return gets no answer. As he watches this, a loud laugh interrupts the meeting, revealing to be the masked man introducing himself as Kagetane Hiruko. Rentaro grabs his gun and confronts him, but a small girl, who turns out to be Kagetane's own daughter and Initiator, passes by his side without being noticed. He is seen by her when she stands next to her father, and hears her asking him if she could cut him down.
Rentaro questions his purpose for coming to their meeting, and is told that he is in search of the Legacy of the Seven Stars. Before he can speak further, Rentaro watches and Shougen grabs his sword and is helped by his Initiator while attacking the masked man, but proves futile nonetheless. The men in the room, Rentaro included, begin to shoot Kagetane, but have their bullets sent back at them. Kagetane then leaves a present for Rentaro, and heads out through the window. Sequentially, a man enters the room and announces the president's death, as well as claiming that the corpse's head is missing. Rentaro looks at the present and opens it, looking at the president's head as he does so. Seitenshi, however, dismisses it and explains to them that they must find the Legacy of the Seven Stars before the enemy; or Tokyo will meet its end.
Rentaro is at a shop with Enju being asked for his opinion on several items, until Enju finds a bracelet of friendship and decides to buy it. As they leave the store Rentaro grabs one of the bracelets, which crack when the users lie, and puts it on, trying it out by saying that he loves Enju; but nothing happens. Smirking, he looks at Enju and tells her that they don't work, but Enju confirms that he is telling the truth as she smiles devilishly. Continuing to walk they see Seitenshi on a nearby screen which leads Rentaro to remember the happenings the day before. Enju shakes him out of his thoughts and is told by Rentaro that if a new law allowing is a success, Gastrea infected children are to be treated more like humans, causing her to joyously grip his hand and express her excitement.
Rentaro then watches as a young girl, who turns out to be a cursed child, is being persecuted by the people for stealing. Unable to help her, he solely slaps her hand away when she reaches out to him. The police then arrives and takes her away, leaving both Rentaro and Enju speechless as they badmouth the Cursed Children. When they reach a different area, Enju angrily confronts Rentaro as to why he didn't help the young girl, with her eyes flaring with anger. Rentaro takes her to an alley and explain to her that he was not able to do anything, seeing as she begins to cry. He then asks her if she was someone she knew, with Enju responding affirmatively. Hearing this, he tells her to go back home as he walks towards a person with a scooter; asking said person to hand it over when he shows them his license.
As he drives past several buildings, he looks around until finally locating the small girl and the police men. However, what he witnesses makes him horrified as the young girl is shot multiple times by the police men. As soon as they leave, he rushes to her side and begins to question their motives for doing this. As he holds her, he remembers speaking to Kisara about Civil Security and its job to protect people, which leads him to ponder if said statement is true after what he witnessed. Sadden by the events, he picks the girl up and notices she is still alive. He rushes her to a hospital, leaving her at the care of the doctors. Whilst crossing the street, he is met by Kagetane and his odd looking gun.
Rentaro points his gun at Kagetane as the latter does the same, who tells him to lower his gun. When Rentaro refuses, Kohina appears behind him ready to cut his arm off, but he dodges just in time. However, she proves to be faster, until Enju arrives and saves Rentaro. Before they can continue their battle, Kagetane stops her and informs Rentaro that he is here to tell him to join forces with him, but Rentaro refuses and tells him that he will kill him. Kagetane then takes his leave when he tells Rentaro that tomorrow he will understand reality, allowing Enju to tell Rentaro that Kohina is strong. He then asks her if she could win in a fight against her, but Enju claims that she is unsure.
The next day, while at school, Rentaro gets a call from Enju's school. Quickly arriving, he sees the caller and asks him for Enju, but he solely reveals that there are rumors of her being a cursed child and proceeds to confront him about enrolling Enju in the school without letting them know of her status. An angry Rentaro admits that if he had told them, she would have been rejected. Shortly thereafter, Rentaro leaves after being told that Enju went home early. When he arrives home, he finds nothing. He sits quietly waiting for her until night time approaches. Graving his jacket and an umbrella, he heads out to look for her.
He reaches a location where many of the Cursed Children live, showing them a photo of Enju and asking if they have seen her. However, he is given a negative reply but is told that they will bring their elder. The elder, Matsuzaki, comes outside and converse with Rentaro about the Cursed Children, all being female, and informs him that he does not know where Enju is. Before he leaves, however, the elder questions if losing Enju would be better for her, causing Rentaro to turn around and yell at him, telling him that he knows nothing of his bond with Enju. The following day, Rentaro is called once again by Enju's school, heading there quickly. Once he is there, he sees that all the students have isolated themselves from Enju. Unable to watch this, he gives her teacher her shots and leaves to where his sensei is. The two talk, and after Sumire comments on how the Cursed Children might be entities sent by god to rid the world of its pollution, Rentaro gets up and angrily informs her that Enju is a human. However, understanding her words, he leaves with the thought in mind that Enju is his family. He leaves to see Enju, but gets a call on the way telling him that she is in a rather risky situation.
Legacy of the Seven Stars arc
Arriving to her school, he hears the kids around him bullyinh Enju due to the recent discovery that she was an Intiator. Lowering his head and retaining his anger, Rentaro continues to search for her as he thinks to himself that Enju is more human than the kids at her school; finally locating her in a group of kids confronting her. Unable to bare the happenings, he approaches her from behind and tells her that they will transfer school, but she refuses to accept it: as she is friends with the kids at her school. Rentaro hugs her, stating that they are not her friends anymore and affirms that they will not view her as one. Suddenly, he gets a call from Kisara. Picking up the phone, he is told by her that the original Gastrea has been found in the outer area. She tells him to listen to a news that will surprise him: the Gastrea is flying in the sky. Quickly enough, telling him that they must be the first to arrive, she hangs up and a helicopter arrives to pick them up.
As they fly in the air, Rentaro catches sight of a kite, but takes a closer look and realizes it is the Gastrea; remembering Sumire's claim of it learning an ability. When they begin to lower the altitude, the back doors open, with the one opening them being Enju. Rentaro watches as she jumps and attacks the Gastrea. Ordering the pilot to lower the altitude, he realizes that it will take too long. He grabs on to a rope and begins to descend to the ground. However, he slips and, in midair, falls head first, but in the nick of time repositions himself and lands on his legs. After rolling on the ground from the fall, he sees an angry Enju fighting the Gastrea.
He watches as she completely dominates the Gastrea, and, when she finishes, heads towards her direction and, hearing her desire to protect everyone whilst crying, hugs her tightly. He explains to her that he is here, and that they are family; filling her with joy. Before he can grab the case Rentaro is ambushed by Kagetane, while Enju faces Kohina. The two being to fight, but Rentaro's abilities prove futile. Leaving him panting, Rentaro tells Enju to run away as he shoots Kohina. After Enju leaves, Kohina comes behind Rentaro and stabs him with her blades. However, he somehow manages to pick himself up and come near a river. With his final words to Kagetane being for him to go to hell, he is shot and falls into the river.
Recollecting memories from his past, Rentaro then wakes up, alarmed, and claiming that his body hurts. He ponders his whereabouts when Enju jumps at him and embraces him cheerfully. Moments later, he is greeted by Kisara and begins to eat, asking her to update him for the time he was sleeping. The two are interrupted by Enju, who leaves the room to get something to show Rentaro. Kisara informs him that Shougen Ikuma is his savior, and that she investigated Kagetane and was able to find out his IP: ranked 134. Shocked, Rentaro mentally tells himself that he can't win. The phone rings and Kisara picks up, but quickly hands it to Rentaro as Seitenshi wishes to speak with him. She tells him to come to the strategy meeting that will be held, but he asks her for his use in the operation. She comments on how, if he does not join them, his loved ones will die. Confused, he questions her claim.
However, before he can hear her final words, Kisara hangs up. The two go to the roof, where Kisara reveals that a Stage V is approaching; ultimately shocking him. He is asked by Kisara if he could defeat Kagetane, but before he can answer, Enju arrives and shows him her bag that someone, unknown to her, fixed. Enju calls for Rentaro's attention as she tells him that she is ready to go whenever he is. Speaking to Kisara, he tells her to tell Seitenshi that he will be helping out. He leaves, being told to take care by a blushing Kisara. Once he arrives to Sumire's laboratory, he prepares his weapons and is given AGV Experimental Drugs, but is told that using it should only be a last resort. Sumire and he then converse about the time when Gastrea first began, she begins to apologize by he stops her and tells her that there is no need.
He walks away while telling her that he will be back, causing her laughter. Arriving to the take off location, they encounter Shougen and Kayo. After thanking him for saving his life, Rentaro is told to go home, but he refuses. Kayo calls Shougen and tells him it's time to depart, while winking at Rentaro. Enju and Rentaro also ready for take off.
Inside a dark cave, Rentaro is asked my Enju if he could turn the flashlight on, which he does but reminds her that they must keep a low profile so the Gastrea will not find them. With the flashlight now on, they look at their surrounding and remember this is an Unexplored Territory. Rentaro tells Enju to follow him, as they will head towards the nearby streets. Pondering, he tells Enju that no matter how ridiculously strong Kagetane is, he would not be hiding in a forest infected with Stage III and IV Gastrea. Before he can end his sentence, she jumps him, trying to keep him from being seeing from a Stage IV Gastrea. The two get up, with Rentaro thanking Enju for saving them.
Suddenly, a loud explosion is heard. Rentaro insults the person's intelligence as the explosion has awaken the forest. True to his statement, a Gastrea stands behind them. Rentaro, asking Enju if she could carry him, tells her to run. Running away from the Gastrea, Rentaro tells Enju that he is counting on her, which causes her to jump high in the trees. However the Gastrea proves to be speedy. Nevertheless, Enju jumps on its head and with the accumulated momentum jumps high near a cliff, and from the cliff she then jumps yet again. As they "fly", Rentaro sees "Ladder of Heaven." Once they land, they continue to search the area, until Enju has a gun pointed at her head.
Rentaro questions Kayo's injuries whilst treating them, only to be told by the young girl that she is Shougen's Initiator. When he tries to introduce himself as well, Kayo interrupts him as she reminds him that she is well aware of who he is. Seconds later, Rentaro ponders Enju's sudden anger towards Kayo, but is told by Kayo that her reasons should be obvious. However, Rentaro remains clueless. As they change topics, he asks her if she got lost from Shougen, realizing that his way of asking sounded extremely childish shortly afterwards. Moments later however, he questions the contents inside the case in Kayo's possession, with the young girl refusing to open it. Albeit, she decides to reveal its contents nonetheless. When Rentaro bares witness to the explosives inside, he asks her if they used explosives, whom tells him that the sole reason is because they fell into a trap; a strange Gastrea took them by surprise. As Kayo explains to Rentaro, he listens and concludes that the Gastrea possesses Rye and Firefly genes, his intelligence amazing Kayo. He is complimented on his knowledge, but refuses to accept it, only to be told by Kayo that she is slightly jealous of Enju. Rentaro questions her words, with Kayo revealing that her Promoter, Shougen, views the Initiators as noting more than tools.
Angered by her words, he clenches his fist and states that she is wrong, claiming that they are not tools. When suddenly, he is asked if he has ever killed anyone before, as she has, which angers him further. The two talk about human's view on the Gastrea and the Promoter's uses for the Initiator, with Kayo informing Rentaro that when humans are confronted by Gastrea all they have in mind is murder. However, before she can continue, Rentaro grabs her and pins her on the ground, informing her of the time Enju almost killed a person: she waited for the person to recover. Kayo interrupts him and claims that his words are just mere words, but that she does not want to deny them. Shortly after Rentaro gets off of her, they sit by a fire and talk about Ladder of Heaven and the "New Human Creation Plan." As they continue to converse, Kayo gets a call from Shougen, who tells her that they have located Kagetane, quickly heading out with Rentaro and Enju after getting her things ready.
Along the way, Rentaro begins to ponder what Kayo's genes could possibly be, earning a kick from her as she feels that he was thinking about her. When they finally arrive to a port, Rentaro inspects his surrounding and is told to keep quite by Kayo. When suddenly, a Gastrea appears from behind the trees, only to be quickly defeated by Kayo; Rentaro and Enju are left speechless. As soon as she defeats the deer-like Gastrea, several others appear behind her, but fall into the ground as she reveals that cogitation is her ability. Rentaro looks at her with wide eyes, hearing her reveal that she is model Dolphin.
Rentaro stands behind Kayo as the latter speaks to Shougen on the phone, the man urging them hurry to the port as he claims that by the time they arrive the battle will be surely over. Walking to the port, Rentaro stops behind Kayo and tells her that he now understands her intellectual speech patters after the revelation of her model, admitting that he thought she had the genes of a deer. Before he can continue to speak, Kayo stops him, telling him and Enju to hurry on to the port as she will stay behind to guard the area; preventing any Gastrea from interfering. Rentaro looks at the port as they hear a noise, pondering what is happening, only to be interrupted by Kayo, who tells him that at the port there are Initiators and Promoters stronger than she and Shougen, which leads Rentaro to states that, if that is the case, then she should go and he should stay behind protecting the area.
Rentaro is slapped by Kayo, being told that he and Enju will contribute greatly in means of combat. However, he questions if she just expects them to leave her behind. He is quickly told that if it were Shougen, he would have no problem leaving her behind, or getting a new Initiator. Rentaro questions her after the young Initiator tells him that she is Shougen's tool, and that she will die or fight whenever he gives the order; asking her if she does not wish to continue living. As Kayo walks away, Rentaro tells her that he could never forgive a person like Shougen. However, he hears Kayo states that she will not attempt to change his view of Shougen, but reminds him that she never said that she was going to die, as such an order was never given to her. He can only watch as Kayo turns her head and asks him to watch over Shougen for her.
Running down the hill that leads to the port, Rentaro hears Enju claim that she is happy to be his Initiator, with him sorrowfully looking down and agreeing. They reach the port, but are met by silence. Soon enough, they hear a stomp behind them, noticing that it is Shougen: they rejoice at the thought of victory. Taking a closer look, however, they see Shougen's own sword buried in his back, leaving him senseless as he confuses them with Kayo. Rentaro can only stare as he asks Enju, whom he thinks is Kayo, to take him to Kagetane so they can finish their fight. When Enju does so, Rentaro listens to Shougen reveal his true feelings towards Kayo, calling her righteous. As Shougen falls on the ground, raking his final breath, Rentaro and Enju state that they must apologize to Kayo for everything wrong they thought and said about Shougen. However, they remind themselves that Kagetane and Kohina must be dealt with first; the final battle. They head towards their location, with Kagetane noticing their presence and reminding Rentaro of their first meeting. The four look at each other as they ready to begin their battle.
Intensely gazing towards Kagetane and Kohina, Rentaro advises Enju to brace herself for the upcoming confrontation, to which she replies affirmatively. Hearing Kagetane call him once more, Rentaro is reminded by the masked man that they shall make their final encounter grand, bearing witness to Kagetane's Maximum Pain as the man quickly employs the technique to destroy that on which they stand. Rentaro is grabbed by Enju, avoiding the attack just in time as the latter jumps high in the air. However, the two are quickly separated when Kohina appears from within the smoke and aims her blades at Enju. Looking towards the ground, Rentaro braces himself for the landing, successfully turning his body to land on his feet. Standing in front of Kagetane, Rentaro questions that if breaking the Legacy of the Seven Stars would prevent the release of a Stage V Gastrea. Quickly enough, Kagetane informs him that it is impossible, as he will prevent him from doing so. Nevertheless, Rentaro grabs his Springfield XD and claims that he will breakthrough in order to achieve his goal. Meanwhile, a small Electronic Eye watches the two from above.
Rentaro is eventually overpowered by Kagetane, who admits that he expected more of the boy. From the ground, Rentaro can only pant and sarcastically apologize for the disappointment. With Rentaro's gun in hand, Kagetane calls him weak just as he returns the weapon and begins to walk away, much to Rentaro's anger. Picking himself up, he tells Kagetane to wait as he acknowledges that he is, indeed, weak, and thus why everyone can't trust it. Momentarily, Rentaro shoots towards Kagetane's direction multiple times. Clashing with Kagetane, Rentaro is pushed back by the pressure, landing on his feet as he claims that he will do whatever it takes to defeat him. However, he only receives laughter in return. Gripping his right arm, Rentaro recalls Kayo's words as Kagetane fires his bullets. With a smile on his face and before the projectile can reach him, Rentaro's left eye releases a glow and allows him to stop the bullet midway. As he releases the bullet from his grip, the skin encompassing his arm begins to deteriorate. Just then, Rentaro reveals his Varanium-infused limbs, informing Kagetane that he is a Mechanical Soldier from the New Human Creation Plan.
Displaying his Varanium limbs, Rentaro is told by Kagetane that he now understands why he took a liking to the young boy; promptly stating that they are one and the same. Just then, Enju calls out to him, reminding him that he once swore to never utilize that power. However, Rentaro interrupts her and inquiries her trust for him. She quickly reassures him with a loud cry. With a smirk on his face and full of confidence, Mechanical Soldier Rentaro Satomi steps forward and induces Kagetane to come at him. Kagetane releases his Maximum Pain, whilst Rentaro counterattacks by releasing the cartridge inside his right arm and delivering a vigorous punch at the incoming attack; successfully blasting a hole through it and, concurrently, demolishing his Repulsion Shield. Feeling the full brunt of the attack, Rentaro hears Kagetane declare that his actions are unbelievable.
Rentaro turns his head to see an angry Kohina approach him with her blades; but before she reaches him, Enju intercepts her swords by utilizing her right foot. He is grabbed by Enju as she tells him that it is time to go. Howbeit, Kagetane grabs both his guns and begins to shoot at them whilst screaming joyously. Enju reaches a certain location before commencing her plan with Rentaro. As Enju heads to attack Kagetane, Rentaro faces Kohina; using a Flashbang to blind his opponent. Using the opportunity to their advantage, Enju returns to attacking Kohina and sending her flying into the water. At the same time, Rentaro appears behind Kagetane ready to attack, delivering a strong kick alongside Enju that sends him in the same direction as Kohina.
The two rejoice, but not for long as Rentaro takes note of Enju's injured arm. Quickly treating the wound, he informs Enju that they will begin to search for the Legacy of the Seven Stars. Albeit, Kagetane and Kohina reappear, leaving Rentaro in pure shock. As Kagetane releases his Maximum Pain, Rentaro tells Enju to carry them away elsewhere. Nonetheless, Kagetane and Kohina are just as quick—appearing behind the two as they reach a stop. The group commences to converse, with Kagetane revealing that his motives for attaining the Legacy of the Seven Stars is so that people like him can continue to fight, angering Rentaro. Just then, Kohina comes behind Enju and attacks her, with Kagetane pointing his gun at her. Rentaro recalls that they are Varanium bullets, standing in front of Enju to protect her from the multiple bullets fired by Kagetane. Momentarily, he remembers his conversation with Sumire about the AGV Drugs he was given; claiming that he will gain superhuman healing abilities. He injects one into his abdomen and releases a powerful cry as he remembers Sumire reveal to him that he may forfeit his humanity.
The bullets within Rentaro's body rapidly exit, the young Promoter clenching his teeth as Enju calls out his name. Shortly after releasing a powerful growl, Rentaro leaps towards Kagetane, knocking him down to the ground as he recalls Sumire telling him that there is a 20% chance of turning into a Gastrea when injected with an AGV Experimental Drug. Regardless, Rentaro remains on top of Kagetane whilst his right eye releases a glow. He watches as the enemy takes his gun and points it towards Enju, rapidly grabbing the latter's gun and redirecting the bullet towards himself. Nevertheless, the wound quickly heals itself; Rentaro lands a strong punch on Kagetane's mask, nearly shattering it. Kagetane aims his gun at Rentaro, shooting multiple times as Rentaro continues his assault. However, Kagetane claims that Rentaro has finally abandoned his humanity, leading him to cease his attack. Moments later, Rentaro feels Kagetane's palm on his waist, a strong pressure arising as Enju shouts for him to get away. Before he can, however, Kagetane utilizes his Endless Scream to create a massive void in Rentaro's body. He can only lay on the ground whilst Enju approaches him, pondering her tears as she falls to the puddle of blood forming around his body.
Shortly afterwards, Kagetane looks at Enju, stating that it is her turn as Kohina appears behind her. Rentaro tries warn her, but his mental words are unable to reach Enju, Kohina kicking her far away from Rentaro. Just then, Rentaro watches, unable to move, as Enju is mercilessly shot by Kagetane with his Black Bullets.
Tendo Combat Style: Rentaro possesses beginner skills in combat derived from the Tendo Style. This style of combat allows him to perform several techniques with offensive properties, such as using his limbs to deliver powerful blows at his opponents.
- Tendo Combat Style: First Style, Number Three (天童式戦闘術 一の型 三六番 Tendo Shiki Sentō Jutsu Ichi No Kata San Ban): When the first style, number three, of the Tendo Combat is in place, Rentaro is granted with superior battle abilities. Further; it is parent to one known technique that is to be utilized when this style of the Tendo Combat is in place. When utilized, Rentaro is able to release a fierce punch that can break through strong defenses.
- Rokuro Kabuto (轆轤鹿伏鬼, ろくろかぶと, Rokuro Kabuto): After employing a specific style of the Tendo Combat, Rentaro puts his left arm in front of his chest, and positions his right arm behind his waist. Clenching his right fist, and with the accumulated vitality, he unleashes a vigorous punch capable of breaking through the highly acclaimed Maximum Pain and the shield that earned the title of the strongest defense, Repulsion Shield.
- Tendo Combat Style: First Style, Number Eight (天童式戦闘術 一の型 八番 Tendo Shiki Sentō Jutsu Ichi No Kata Hachi Ban): This first style, number eight, of the Tendo Combat, grants Rentaro supreme melee abilities. Further; it is parent to one technique that is to be utilized when this style of combat is in place. When in use, it is noted that it enhances the power of the normal punch.
- Tendo Combat Style: Second Style, Number Sixteen (天童式戦闘術 二の型 十六番 Tendo Shiki Sentō Jutsu Ni No Kata Jūroku Ban): The Tendo Combat, second style, number sixteen, grants Rentaro supreme combat abilities. Further; it is parent to two diverse techniques that are to be utilized when this style of the Tendo Combat is in place. When Rentaro Satomi employed this technique on Kagetane Hiruko it proved futile, as the latter solely stood there and felt no harm. However, whilst speaking to Sumire Muroto, Rentaro states that he is a beginner of the "Tendo Combat Style," hinting that his expertise in this style of combat is limited.
- Hidden Bullet: Sky Wind (隠弾 • 黒天風, いんぜん • こくてんふう, Inzen Kokutenfuu): After employing the Tendo Combat Style: Second Style, Number Sixteen, Rentaro thrusts his body at the opponent with accumulated speed, and, using the momentum, delivers a powerful back kick strong enough to send the opponent flying backwards.
Enhanced Speed: Rentaro displays impressive speed, having the ability to approach his targets up close from long distances in just a matter of seconds.
Enhanced Durability: Rentaro has shown on numerous occasions to possess a high degree of durability, taking several hits from Kagetane and rising to his feet quickly. During his fight with Shougen, he takes a hit to the forehead and seemingly endeavors said assault; regaining his stability shortly afterwards. Further, he was able to withstand Kagetane's many kicks to the face and his Maximum Pain to a noteworthy time.
Enhanced Reflexes: Rentaro possesses fast reflexes, having been capable of evading a fast approaching Kohina when the latter attempted to take his life with Short Swords, as well as when he was confronted by Kagetane on numerous occasions.
Hand-to-Hand Combat: Due to his style of combat, Rentaro packs a set of durable melee assaults, such as when he delivers two consecutive hits on Kagetane's face and a kick to his neck.
Springfield XD (スプリングフィールドXD Supuringuhuīrudo XD): Rentaro is in possession of a, as he states, normal black gun. He carries the gun on the back of his pants, using it when he is the midst of a fight. He has shown great mastery over said weapon, shooting a Stage I Gastrea repeatedly without showing any signs of fatigue and with the ability to maintain his stability throughout the process.
- Black Bullet (ブラック・ブレット Burakku Buretto): With his gun, Rentaro's main projectiles of choice are Black Bullets, which are created from the very same object that keeps Gastrea away from the Monoliths, Varanium. He himself states that with said bullets, Gastrea will not be able to recover; giving him the upper hand when in combat. These Black Bullets were able to harm a Stage I Gastrea greatly, in contrast to when Tadashima attacked with regular bullets; to no effect.
AGV Experimental Drug (AGV 試験薬 Shiken Kusuri): Rentaro was given five needles by Sumire that contain AGV Experimental Drug within. He was told by Sumire herself that this Experimental Drug contains artificial Gastrea Virus that grants him superhuman healing abilities, and is only to be utilized as a last resort weapon; the user may forfeit their humanity. When Rentaro injected himself with a needle in his abdomen, he releases a loud and vigorous roar that intimidate those around him.
- Superhuman Healing Capabilities: After injecting himself with a sole dose, Rentaro's wounds begin to heal instantaneously. Additionally, Black Bullets, previously shot by Kagetane, exit his body, with the wounds healing themselves and appearing unharmed; smoke arising and evaporating into the air. The speed at which the wounds can heal themselves appears to be rather swift, as a wound caused by a bullet heals in a mere amount of seconds.
Flashbang (閃光弾 Senkō-dan): When Rentaro places a Flashbang into effect, a bright light and disturbing sound to the ears surround the area around his opponent; rendering two of their senses ineffectual. This non-lethal weapon is additionally used as a form of diversion for future assaults.
When the two first met, Enju's distrust in humans lead their encounter to a rocky beginning. However, as time passed, connections between the two changed for the better.
Rentaro treats Enju like family, albeit; Enju seeks for a deeper relationship with the Civil Security member which usually comes off in a comedic manner. Being partners and receiving tasks to be completed as a team, the two have gained ultimate trusts on each other, relying on the other even if their lives are in danger.
During a mission to take down a Stage I Gastrea, Enju plants a kiss on Rentaro's lips, but soon enough kicks him for leaving her behind, claiming herself to be his fiancé. Despite this, however, she displays supreme adornment to his skills; noting his bravery when he fought and overpowered said Gastrea alone. Rentaro believes that Enju is just as human, or even more, as the people around her, even to the point of admitting that he will guide Enju through the correct path. When people refer to Enju as a monster, Rentaro is unable to keep his emotions in control; bursting out in angry cries as he defends her image. Said statement is further proven true when the boy receives a phone call from Enju's school informing him that her identity of being a cursed child is public, rushing to her side (desperately looking for her in the process) in mere seconds and consoling her as well as protecting her from the kids calling her a monster.
When they were alone in a forest where Kisara located the original source of the Gastrea, Enju admits to Rentaro that she wishes to protect everyone, whilst her vision is clouded by tears falling down her face. Moved by her words, Rentaro hugs her tightly and reminds her that, even though she is accused of things she did not commit, he will always be by her side as any family would. Enju then weeps as she embraces Rentaro. Henceforth, the bond between the two has ultimately strengthen.
Kisara is one to usually badmouth Rentaro's abilities and lack of responsibilities: calling him useless, an idiot and even threatening to kill him. Although at oftentimes it arises as conflicts between the two, they don't remain arguing for long. Rather; continue displaying their family-like bond. Kisara holds great respect for Rentaro's bravery, however, seeing as he saved her from a rampaging Gastrea when she was young and the two were living under Kikunojyo Tendo's care, as well as when Rentaro heads out to fight Kagetane, she gives him her full trust on victory. When Rentaro witnesses Kisara's sorrow over an issue with the Tendo and her parents whilst the latter talks in her sleep, he assures her that he will avenge the Tendo.
Although not much is known of the relationship Rentaro shares with Kikunojyo, it has been stated that when Kikunojyo first offered Rentaro his own home to live in as a Tendo, the young boy denied. However, as time progressed, Rentaro undoubtedly accepted and lived under his care. Kikunojyo also protected Rentaro against a Gastrea, and gave him the advice to live rather than die in despair.
Miori is a fellow classmate of Rentaro at Magata High School. Miori is the president of the Student Council at their school and daughter of the president of Shiba Heavy Weapons. The two first met at some point prior to the beginning of the current story. Her company is also responsible for distributing the Varanium bullets he uses, which he receives for free. According to Miori herself, their were conditions met with Rentaro obtaining free bullets, as such were studying in the same school. She is seen to have feelings for Rentaro as on few occasions she has tried to seduce him, leaving him uncomfortable. She is often willing to help him when he asks her a favor, such as requesting information on Sogen, but she always requires something in exchange, such as spending time with him, and uses their time alone to her advantage, although the moment was obstructed by Kisara.
Syouma is an old friend of Rentaro, and his martial arts superior. The two seem to be well-antiquated and get along very well. Rentaro has a deep respect for his abilities and addresses him as Syouma-nii.
When Rentaro first met Kagetane, the two fought and introduced themselves whilst in the midst of it all. Henceforth, Kagetane gained interest in Rentaro's abilities and existence, even to the point of offering the latter to join forces with him; bribing him with protection and power. Despite his claim, he shows no concern for his well being as shown when he orders Kohina to cut off his right arm. In addition, Kagetane has stated on numerous occasions, and has proven himself, that he solely wants to kill Rentaro. When Rentaro denies his offer, he is met by cold shoulders. On the other hand, Rentaro feels nothing more than utter disgust when confronting Kagetane. He is usually the first to attack the masked man and does not care for his ideals.
Ten years ago when Gastrea first began to overtake mankind in the food chain, Sumire claims to of had done something ultimately unforgivable to Rentaro, but Rentaro seems to hold no gourde against her for her unknown dilemma. Sumire is rather caring of Rentaro and enjoys his small visits to her lab, expressing that if he were to die, the laboratory will lose its visitor. When she hands him AGV Experimental Drugs, she informs him not to use it unless it's a must, afraid to lose his company. Rentaro is also quick to consider listening to Sumire's opinions, calling her his "Sensei" and even claiming that she is an expert. When he visits her lab, Sumire usually plays pranks on him by scaring him with objects in her lab, knowing Rentaro's cowardliness very well. Additionally, she pesters him with Kisara refusing to be his girlfriend if he continues to act weak. When it comes to Rentaro's abilities, Sumire is one to quickly criticize.
Shougen and Rentaro share a conflicting relationship, with Shougen usually expressing his discomfort of Rentaro's presence and lack of experience. When the two first met, Shougen quickly confronted the young boy after being asked to introduce himself; smashing his head strongly against Rentaro's and sending him back. Rentaro also dislikes Shougen's view on the initiators, whom he refers to as "tools" to use in combat. Despite this, Rentaro admires Shougen's strength and can only ogle his force when the man clashes with Kagetane. During the time Rentaro went after the Gastrea, Seitenshi requested be killed, Shougen brings him to the hospital after he is left at death's door by Kagetane. However, before he leaves the hospital, he tells Kisara that Rentaro is simply an onerous brat. Before starting the mission to bring down Kagetane, Shougen sees Rentaro at the place of departure and, calling him a hindrance, advises him to go home. Although, Rentaro denies, which leaves Shougen open-mouthed. Before parting ways, Shougen orders Rentaro not to get in his way after hearing him thank him for saving his life.
Rentaro has displayed apathy for Kayo's condition, questioning if she is okay with the fact that a Promoter's orders are absolute. He has also treated the injuries inflicted upon her by a Gastrea, and shared with her his feeling towards the Initiators; calling her human and family. Kayo, on the other hand, believes that Rentaro's words are nothing but mere words, but she does not wish to deny them. Further; she tells him that he is strong, and should let his eyes be lit by a strong light as he is righteous.
A young Cursed Child Rentaro and Tina run into at the mall. Rentaro seems to be on friendly terms with her and also shows to care for her.
Appearances in Other Media
A Day of Civil Securities
Walking about in the streets of Tokyo, Rentaro passes by a man that is coughing violently. Stopping and asking if he is fine, he is met by a bloody hand to his face, and the man asking him for help. Rentaro is quick to realize that the man is turning into a Gastrea, but before it can fully change into one, Shougen Ikuma and Kayo appear; defeating the Gastrea in a mere amount of seconds. Rentaro complains about them taking his target, though Kayo questions what kind of Civil Security talks so nicely to a Gastrea. He looks up as she begins to rant about the duties of being a part of Civil Security, mainly noting the fact that his Initiator is not with him. Before he can reply, they leave. From behind, Tadashima calls Rentaro's attention and tells him that it was nicely done. However, not accepting the complement as he knows it was Shougen that defeated the Gastrea alone, Rentaro comments on their different jobs: Police and Civil Security. Seconds afterwards, he gets a call from Kisara, whom he informs of the Gastrea that appeared before him, but was taken by another company. Arriving back to the company, he is met by a worried Enju telling him that the president is not acting like her normal self. Much to his shock, he witnesses this when she walks in front of him acting like a neko. Though she quickly returns to her former self when she tells Rentaro that there are Gastrea Stage II close to their location, as well as telling him not to mess it up. When they hear an explosion, Rentaro and Enju rapidly head towards it. Arriving to the location, Rentaro begins to evacuate the civilians. However, Shougen approaches him and, grabbing him by the neck, tells him not to get in his way. Rentaro, on the contrary, says that he's the one getting in his way to protecting the innocent. Before they can finish their conversation, Enju passes in front of them and kills a Gastrea, shocking Kayo. Rentaro and Shougen, standing by their Initiators, ready their weapons for battle.
- (To Tadashima) "Well... Just Relax... And leave it to me!"
- (To Enju Aihara) "That's why I must show her the way. As her partner."
- (To Kisara Tendo) "It's none...of your business... Every single time, you're annoying."
- (To Kikunojyo Tendo) "My father and mother aren't dead! They must be waiting somewhere for someone to save them! I... Must find them..."
- (To Sumire Muroto) "I-I can protect Kisara-san right now!"
- (To Kisara Tendo) "If you want to make money, then just hire someone who is stronger than me! Isn't that right, president?!!"
- (To Shougen Ikuma) "Not as detestable as you."
- (To Enju Aihara) "If the bill is passed, the Cursed Children will no longer have to be abandoned. They'll also have houses to live in. They can sleep cozily inside futons, and will no longer suffer from starvation."
- (To Himself) "Just what is right and what is wrong...? To begin with, just who is the enemy I must defeat?"
- (To Kagetane Hiruko) "You really have a horrible taste in guns, Hiruko Kagetane."
- (To Enju Aihara) "The reason why I still want to live in this rotten world of ours is—It's because you're here, Enju."
Battles & Events
- Rentaro Satomi vs. Kagetane Hiruko
- Rentaro Satomi, Enju Aihara & Tadashima vs. Sumiaki Okajima
- Rentaro Satomi vs. Shougen Ikuma
- Civil Security Corporation vs. Kagetane Hiruko
- Rentaro Satomi & Enju Aihara vs. Kagetane Hiruko & Kohina Hiruko
- Rentaro Satomi, Enju Aihara, Shougen Ikuma & Kayo Senju vs. Stage II Gastrea
- Takaharu & Mafuyu's Funeral
- Rentaro Satomi Becomes a Tendo
- Cleansing the Tokyo Area
- My Savior...
|Promoters||Rentaro Satomi • Tamaki Katagiri • Kisara Tendo|
|Deceased||Shougen Ikuma • Shouma Nagisawa|
|Revoked||Kagetane Hiruko • Ayn Rand|
|Male||Rentaro Satomi • Kikunojō Tendo • Sōgen Saitake • Tamaki Katagiri • Sogen Saitake|
|Female||Enju Aihara • Kisara Tendo • Seitenshi • Tina Sprout • Yuzuki Katagiri • Asaka Mibu • Miori Shiba|
|Left||Kagetane Hiruko • Kohina Hiruko|
|Deceased||Shougen Ikuma • Kayo Senju • Midori Fuse • Shouma Nagisawa|
|Offspring||Kisara Tendo • Several Men|