Kaiju No. 8 Characters

A 32-year-old who clears away kaiju corpses for Monster Sweeper Inc. after failing the Defense Force exam again and again, and who has all but given up on a childhood promise to fight beside Mina Ashiro. A small parasitic kaiju turns him into a humanoid kaiju with a fortitude of 9.8, which the Defense Force codenames Kaiju No. 8. He scrapes into the Third Division as a cadet while hiding it, drawing 0% from his combat suit at the exam but making up for it with everything he learned taking kaiju apart. After he transforms in public to save Tachikawa Base, Director General Isao Shinomiya spares him as an asset, and in season 2 he fights with the First Division while each transformation threatens to leave him less human.

The 27-year-old captain of the Third Division and Kafka's childhood friend, with whom she made a pact to fight kaiju together. She is one of the strongest officers in the Defense Force, a marksman whose personal weapon is a massive handheld cannon built for bringing down giant kaiju. She cannot wield blades herself, which is why she asked the swordsman Soshiro Hoshina to be her vice-captain. When Kafka is exposed as Kaiju No. 8 she speaks up for him at headquarters, and in season 2 she takes on giant kaiju from across the city with a rail gun.

An 18-year-old who joins Kafka's cleanup crew while preparing for the Defense Force, and who talks Kafka into trying the exam one last time. He is with Kafka in the hospital when he first transforms, helps him keep the secret and joins the Third Division alongside him. After the Third Division's base is wrecked he moves to the Fourth Division, where he proves compatible with Numbers 6, the ice-controlling weapon made from Kaiju No. 6. The suit's strain nearly overwhelms him on his first mission before he learns to use it.

A prodigy who records the highest unleashed combat power of any recruit, and the daughter of Director General Isao Shinomiya and Hikari Shinomiya, a former Second Division captain killed fighting Kaiju No. 6. Her father's demand that she be perfect drives her hard. Kafka saves her life at the exam, and she keeps his secret. She fights with a giant axe, moves to the First Division with Kafka under Gen Narumi, and in season 2 inherits her mother's Numbers 4, which lets her fly.

The Third Division's vice-captain, a swordsman who was told for years to give up on the Defense Force because he was poor with firearms, until Mina asked him to be her second. Cheerful and teasing on the surface, he suspects early on that Kafka is hiding something, recommends him as a cadet partly to keep an eye on him, and fights Kaiju No. 8 at Sagamihara without knowing who it is. In season 2 he wears the captured Kaiju No. 10 as a Numbers weapon with a mind of its own, and trains Kafka in hand-to-hand combat.

The captain of the First Division and the Defense Force's strongest active fighter, who is lazy and childish off duty and entirely serious in battle. He wears Numbers 1, made from Kaiju No. 1, whose suit and retinal implants let him read an enemy's movements before they happen, and carries a large rifle with a bayonet. When Kafka and Kikoru join his division he demands that Kafka prove his strength, and he trains Kikoru for the fight against Kaiju No. 9.

The Director General of the Defense Force and Kikoru's father, a formidable fighter who wears Numbers 2, made from Kaiju No. 2. Hardened by his wife's death, he pushes his daughter relentlessly. He fights Kafka himself to test him, then spares him, calls him by his name and tells him to prove his worth. In season 2 Kaiju No. 9 kills and absorbs him, taking his Numbers 2 weapon.

A hot-headed recruit who joins the Third Division with Kafka, Reno and Kikoru and, placed in the same platoon as Reno, quickly makes him his rival. He is badly hurt when Kaiju No. 9 ambushes him and Reno at Sagamihara. Transferred to the Fourth Division with Reno, he breaks through the ice when Numbers 6 overwhelms his friend, carries him clear and then opens the way for Reno's winning shot.

A platoon leader in the First Division who fights with a minigun and deeply respects Captain Gen Narumi. In the last episode of season 2 she leads the First Division's officers against Kaiju No. 13 and is about to be killed when Kafka arrives to save her. She is voiced by Kana Hanazawa in Japanese and Emi Lo in English.

The captain of the Fourth Division, who takes in Reno and Iharu after the Third Division's base is wrecked. He oversees Reno's trials with Numbers 6, warning him that Numbers weapons are dangerous and can shorten a user's life, and gives him a month before testing him on a real mission. Afterwards he tells Mina he believes Reno can wield it.

A humanoid kaiju that can create other kaiju and absorb people to take on their appearance and memories. It first strikes during the entrance exam, then hides among the cleanup crews disguised as a worker named Takamichi Hotaka, and can wrap an area in a mimetic space that cuts off communications. In season 2 it kills and absorbs Isao Shinomiya, takes his Numbers 2, and sends waves of new numbered kaiju against Japan.

A humanoid kaiju created by Kaiju No. 9, which leads a flock of wyvern-type kaiju against Tachikawa Base and goes straight for Soshiro Hoshina as the strongest fighter there. Defeated by the Third Division and captured alive, it trades what it knows about No. 9 for being made into a weapon for Soshiro. It becomes the first sentient kaiju turned into a Numbers weapon, a suit with a tail that keeps its own mind and at first struggles to fight in step with its wearer.