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Muroto Sumire
Sumire Muroto

室戸 菫
(むろと すみれ)


Sumire Muroto






Female Female


March 14

Hair Color


Eye Color


Professional Status


Base of Operations

Magata Public University Hospital

Personal Status


Light Novel Debut

Tendo Civil Security Corporation

Manga Debut

Chapter 3

Anime Debut

Episode 1

Japanese Voice

Yūko Kaida

English Voice

Joanne Bonasso

Image Gallery

"Corpses are good. They don't babble. Only they can understand my feelings."

— Sumire Muroto in "The Cursed Children"

Sumire Muroto (室戸 菫, むろと すみれ, Sumire Muroto) is a researcher at the Magata Public University Hospital, which is a medical school near Magata High School, and is Rentaro Satomi's teacher. She is one of the Four Sages and is the person in charge of the "New Human Creation Plan" in Japan.


Sumire M

Sumire's full appearance.

Sumire Muroto is a young doctor of average height and body frame. She has messy, purple hair that covers the whole of her forehead, as well as a prominent bang entirely covering her right eye and parts of her cheekbones. Arching around her eyes are a pair of thin eyebrows and, underneath, two slightly thick eyelashes which encompass her oval eyes and light irises. Sumire's hair, which juts out in every direction, but is kept moderately straight in the back, falls directly below her neck. Sumire possesses thin lips and a small nose.[1]

Sumire dons a white, open-coat: true to her profession, that falls below her feet and covers most of her body. Under said garment is a shirt with a large collar circling around her neck, as well as a dark skirt covering her thighs, but leaving her legs' lower regions exposed, which are covered by a pair of dark tights. Around her neck, a small necklace can be spotted, as well as her name-tag located on her coat.[2]


Sumire laughs at Rentaro

Sumire laughs at Rentaro.

Sumire Muroto is an easygoing, charismatic woman. She enjoys playing pranks on Rentaro Satomi, seeing as he is one to be easily scared by eerie happenings.[3] Similarly to how the others around Rentaro call him weak, Sumire is no exception as she shows no pity when naming his faults.[4] Sumire also enjoys toying or misinterpreting Rentaro's words. Despite her carefree and lively persona, Sumire was filled with sorrow when Gastrea first started to take over mankind, stating that not even a thousand words could explain the agony she felt at that time.[5] This was mainly caused by the death of her lover during the Gastrea War, and, descending onto "the path of demons", she was saved through Rentaro's growth as a person.[6] When explaining this to Rentaro, her exact words had been:

"My soul had been saved by your growth. When I had cried out after losing everything I had in the world, I was still connected to the world through your existence. When I hold the banked fire of that shining passion from that time, it is very warm. If you die, I will return to the darkness."[6]


The Cursed Children arc[]

Sumire scares Rentaro

Sumire scares Rentaro.

Sumire, hiding her presence behind a sculpture; personifying the object as she calls it her husband, scares Rentaro when the boy walks into her lab and sees the "moving object." She comments on how he is still weak against creepy things, and then welcomes him to her place, calling it an abyss, as she hugs the sculpture. She informs Rentaro that the Gastrea he defeated was brought to her lab, and confronts him for not killing it more cleanly. She approaches his face and tells him that the impact of the bullets damaged the meat and are all over its body. She compares Rentaro to Nobi Nobita from the a popular manga, claiming that his shooting skills are far better than Rentaro's. She calls him hopeless and questions him for not committing suicide yet, following her dark conversation by asking him if he has already lost hope in the world. Not receiving a direct reply, she simply takes a seat and admits that if he will act like this Kisara will dump him, making him shudder and blush at the thought. Rentaro reminds her that a person like Kisara would have someone with Rentaro's abilities defeated in mere seconds. However, in return she recollects the time when Rentaro was helped by Kisara when he lived with the Tendo and her brothers would pick on him. Dismissing their conversation, she tells him that it's time to get back on track.[7]

Talking about Gastrea

Sumire talks about Evolutionary Jump.

The two talk about the characteristics of a Jumping spider, claiming that the Gastrea virus gifted the infected with a new ability, calling it Evolutionary Jump. However, Rentaro tells her that he believes it was able to camouflage itself, but Sumire admits that if it is true, the Tokyo Area will be no more by tomorrow. When Rentaro mentions Enju and Civil Security, Sumire begins to recollect the summering Cursed Children during the time Gastrea began to take over mankind. She states that the Gastrea virus was able to give them enhanced abilities. Before Rentaro leaves, she tells him to come visit her again, in a comedic way.[8]

Sumire talks to Rentaro about Gastrea

Sumire talks to Rentaro about "God's wish."

Sometime later, she is visited by Rentaro once again, who comes to her lab asking her for advice on what happened to Enju and the small girl that was shot by the police not so long ago. However, Sumire, distracted, tells him that she was thinking about what snack to eat. She quickly gets serious as she talks about the people that view Gastrea as God's wish to clean the world of its pollution. Commenting on how the Cursed Children are messengers from God to carry out the task of observing the Gastrea and humanity, Sumire is met by an angry Rentaro who tells her that Enju is human. Before he can confront her further, she extends her arms out and informs him that he now understands that he and Enju are family. Rentaro runs out claiming that he now understands, thanking Sumire along the way.[9]

Legacy of the Seven Stars arc[]

Sumire tries to apologize

Sumire tries to apologize.

Sumire greets Rentaro when he comes to her lab to prepare for the upcoming battle against Kagetane. She asks him if what he has is enough, to which Rentaro responds affirmatively. She tosses a pack of AGV Experimental Drugs at him, advising him not to use it unless ultimately necessary. She admits that if he were to die, she will lose her visitor, causing him to smile slightly. She then tells him that when Gastrea first began, her world turned upside down. She questions how to apologize to him for what she did when she "lost herself." However, Rentaro tells her that there is no need as he has no hate for her. Before walking out of her lab, he points his thumb upwards and promises to return, causing her laughter. She tells him to become a good man benefiting of those words, expecting him not to die.[10]

After handing him the drugs, Sumire is instantly questioned about its contents. Briefly, she reveals that originally she was researching for antibiotics for the Gastrea Virus; stating that an AGV Experimental Drug accidentally came to being—a drug that utilizes the Gastrea Virus to grant the user superhuman healing capabilities for an hour, infecting them with the Gastrea Virus.[11] She further explains to him that when the time for him to cross that line comes, it should be within his knowledge that he may forfeit his humanity.[12]

Sumire and Kisara converse

Sumire and Kisara converse.

Sitting in her chair and using her laptop, Sumire turns to look at the visitor knocking at the door, Kisara. The doctor quickly and warmly questions her sudden arrival,[13] only to be thanked by Kisara for saving Rentaro's life; claiming that if not for her intervention, Rentaro would be dead. Sumire attempts to dismiss her gratitude, asking about her abrupt sweetness and even admitting that if she acts this sweet around Rentaro the latter would not hesitate to lupin dive her. Quickly enough, Sumire witnesses as Kisara lowers her head and blames herself for not being able to stop Rentaro from going. However, Sumire, placing a warm cup on the table, reveals that Rentaro would have gone regardless. As she walks towards her laptop, she recites Rentaro's words to Kisara before the latter left to find Kagetane, which shocks her. Subsequently, Sumire admits that she wishes to believe in those words.[14]

Sumire readies to send the data

Sumire readies to send the data.

Moments later, after Kisara leaves her laboratory and heads to the meeting held by Seitenshi, Sumire appears on a television screen, telling the men present to stop praising her when they state that Rentaro's lost limbs look perfectly normal—something which Sumire herself performed when Rentaro was attacked by a Gastrea. Being told by Seitenshi to get back to the matter at hand, Sumire sends data of Rentaro's Varanium limbs,[15] shocking the whole of the meeting as she reveals that Rentaro is a Mechanical Soldier.[16]

Sumire loses hope

Sumire loses hope.

Sumire watches as Rentaro momentarily gains the upper hand; largely overpowering Kagetane with his Varanium limbs. However, the boy is soon impaled by Kagetane's Endless Scream. The doctor is subsequently asked by Seitenshi if utilizing another injection would restore the lost organs. She responds negatively, informing the protector that if he were to inject himself one again with the AGV Experimental Drug, a new Gastrea will be born. Gazing towards the ceiling of her laboratory, Sumire exclaims that it is over.[17]



  • (To Rentaro Satomi) "As usual, you're still weak against creepy things like this."[19]
  • (About Charlie) "Corpses are good. They don't babble. Only they can understand my feelings."[20]
  • (To Rentaro Satomi) "Although Nobita-kun was perverted, lazy, and cowardly, he was at least good at shooting. But not only are you perverted, lazy, and cowardly, you're also horrible at shooting. You're the worst. You're hopeless. I'll ask you bluntly. Why haven't you committed suicide already?"[21]
  • (To Rentaro Satomi) "Haven't you already lost all hope for this world?"[22]
  • (To Rentaro Satomi) "Ten years ago, since the day Gastrea began killing humans, my world turned upside down. Even if I used a thousand words, it wouldn't be enough to express that hell."[23]
  • (To Rentaro Satomi) "At that time, I completely lost myself... I don't know how I should begin to apologize to you...!"[23]


  1. Black Bullet Manga: Chapter 3, Page 14
  2. Black Bullet Manga: Chapter 3, Page 20
  3. Black Bullet Manga: Chapter 3, Page 12
  4. Black Bullet Manga: Chapter 3, Page 15
  5. Black Bullet Manga: Chapter 9, Pages 33-34
  6. 6.0 6.1 Black Bullet Light Novel 2: Against a Perfect Sniper (pg 148)
  7. 7.0 7.1 Black Bullet Manga: Chapter 3, Pages 13-17
  8. Black Bullet Manga: Chapter 3, Pages 18-25
  9. Black Bullet Manga: Chapter 3, Pages 29-35
  10. Black Bullet Manga: Chapter 9, Pages 32-36
  11. Black Bullet Manga: Chapter 14, Pages 37-38
  12. Black Bullet Manga: Chapter 14, Pages 40-41
  13. Black Bullet Manga: Chapter 13, Page 1
  14. Black Bullet Manga: Chapter 13, Pages 3-6
  15. Black Bullet Manga: Chapter 13, Pages 21-23
  16. Black Bullet Manga: Chapter 13, Page 34
  17. Black Bullet Manga: Chapter 15, Pages 16-17
  18. Black Bullet Manga: Chapter 9, Pages 34-37
  19. Black Bullet Manga: Chapter 3, Page 13
  20. Black Bullet Manga: Chapter 3, Page 13
  21. Black Bullet Manga: Chapter 3, Page 15
  22. Black Bullet Manga: Chapter 3, Page 16
  23. 23.0 23.1 Black Bullet Manga: Chapter 9, Page 34