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Anime | Gastrea | Manga
Sumiaki in the Anime
Sumiaki Okajima



Sumiaki Okajima




Male Male

Personal Status





Wife (Divorced)

Light Novel Debut

Tendo Civil Security Corporation

Manga Debut

Chapter 1

Anime Debut

Episode 1

Image Gallery

"There's something...I want to ask of you. Can you help me...Apologize to my wife and child? Tell them... That I am very sorry for what I've done."

— Sumiaki Okajima in "Tendo Civil Security Corporation"

Sumiaki Okajima (純明岡島 Sumiaki Okajima) was a man attacked by a Gastrea, turning into one himself shortly afterwards.


As a human, Sumiaki Okajima was a tall man with a thin build. He had thin eyebrows and slightly thick eyelashes that served as shelter to oval eyes and light-colored pupils. He kept his hair slicked down and jutting forward, pointing towards the right. His big forehead was visible to the naked eye, as well as his small ears, pointy nose and oddly shaped jaw.[1] As a Gastrea, Sumiaki's entire body composition identically changes into that of a jumping spider, spotting four enormous eyes on his head, as well as eight legs for limbs. On his fur-coated back is a set of visible black markings.[2]

During the time he was alive and in his human body, he wore simple black plants and a white shirt, buttoned up and with a pocket on the left side as well as a folded collar.[1]


Sumiaki Okajima seems to maintain his calm even in the pinnacle of the worst situation. Seconds before turning into a Gastrea, and even after looking at his destroyed body, he merely pondered his condition and began to sob exclusively for failing as a husband and father. Even so that his dying words were to tell his family that he is sorry. Previously to being attacked by a Gastrea, however, he was rather lively and sure of his actions.[3]


Civil Security arc[]

Sumiaki looks at his bloody body

Sumiaki's injured body.

Whilst practicing a future conversation to his wife, Sumiaki expresses the joy of his "new job" and even states that he is sorry for what he had previously done; promising to never give up again. He finally gets ready to make the real call, pondering the result, but before he can do so, he turns his head and sees a spider type Gastrea near him. It jumps and attacks him.[4] Walking about, Sumiaki comes across a young girl, whom he asks for directions to his house. However, he is met by an irrelevant reply as she asks him if he has any final words before he dies, alarming him. The two continue to converse, with the young girl telling Sumiaki to look at himself, which he does. Noting his heavily injured body, he recalls the events that transpired minutes before he came across the young girl.[5]

Sumiaki is shot by Rentaro

Sumiaki attacked by Rentaro.

Clenching his fist Sumiaki tells Enju that his final words are an apology to his family, remembering the time he took pictures with his wife and daughter. Soon enough, his body begins to change, causing an explosion. Finally transformed into a Gastrea, he fights Enju and gains the upper hand by releasing some liquid from his mouth, and then swings his leg at her; sending her back. Before he can continue the fight, Rentaro and Tadashima arrive.[6] He turns his head and is, quickly, shot by Tadashima. The bullet, however, has no effect. He jumps and attacks him, but is stopped by Rentaro, who uses Black Bullets to hold him back. After multiple assaults, he lies on the ground as Rentaro approaches him and notes the unscathed backside of his abdomen. Sumiaki awakens and readies to attack Rentaro once again; but he is kicked in the face by Enju. The powerful kick sends the man spinning into the ground and sequentially ends his life.[7]

Afterwards, his corpse is brought to Sumire Muroto's laboratory.[8]


After turning into a Spider Type Gastrea, Sumiaki displays several new techniques. However, he does not retain his self-control.[9]

Sticky Liquid

Sticky Web being used.

  • Spider Web: Sumiaki is able to produce a sticky, dark web from his mouth to attack his opponents, primarily used as a form of distraction.[10] (Unnamed)

Enhanced Strength: With a single snap of an arm, Sumiaki was able to send Initiator Enju Aihara spinning several feet away from him, and destroying a structure behind her with the impact.[11]

Enhanced Durability: Sumiaki was able to withstand a normal bullet from Tadashima's gun without receiving any damage. In addition, he was also able to sustain multiple Black Bullets, created from that which harms Gastrea, Varanium, for a noteworthy time.[12]


  • (To Enju Aihara) "There's something...I want to ask of you. Can you help me...Apologize to my wife and child? Tell them... That I am very sorry for what I've done."[13]

Battles & Events[]




His backstory was removed in the anime adaption.


  1. 1.0 1.1 Black Bullet Manga: Chapter 2, Page 7
  2. Black Bullet Manga: Chapter 2, Page 13
  3. Black Bullet Manga: Chapter 2, Pages 7-10
  4. Black Bullet Manga: Chapter 2, Pages 8-9
  5. Black Bullet Manga: Chapter 2, Pages 4-7
  6. Black Bullet Manga: Chapter 2, Pages 10-18
  7. Black Bullet Manga: Chapter 1, Pages 35-46
  8. Black Bullet Manga: Chapter 3, Page 15
  9. Black Bullet Manga: Chapter 2, Page 13
  10. Black Bullet Manga: Chapter 2, Page 15
  11. Black Bullet Manga: Chapter 2, Pages 16-17
  12. Black Bullet Manga: Chapter 1, Pages 40-43
  13. Black Bullet Manga: Chapter 2, Page 10