Affiliation: Vice-Captain of the Third Division, Japan Defense Force. Birthday: November 21 Height: 171cm Age: 26 Released Combat Power: 92% Background: The second son of the Hoshina family, a prestigious lineage of Kaiju exterminators dating back to the Muromachi period. (His older brother is Soichiro Hoshina, Captain of the Sixth Division.) Speech: Hailing from the Kansai region, he speaks with a dialect (Kansai-ben), giving him a friendly yet sly and elusive air. He is a close-quarters combat specialist who uses dual blades, a rarity in the Defense Force where heavy firearms are the norm. Likes: Reading, coffee, Mont Blanc, simple-minded people.

Affiliation: Captain of the First Division, Japan Defense Force. Birthday: December 28 Height: 175cm Age: Estimated 27 Released Combat Power: 98% Relationships: Direct superior and mentor to the new recruit Kikoru Shinomiya. He brought the protagonist Kafka Hibino (Kaiju No. 8) into the First Division to utilize him as a combat asset while keeping him under surveillance. He uses a specialized weapon that combines a large rifle with a massive blade. He annihilates every Kaiju on the battlefield single-handedly, switching seamlessly between long-range bombardment and close-range slashing. He is easily bored and somewhat prickly. Likes: Freedom, gaming, small spaces, searching his own name online.

Affiliation: Captain of the Third Division, Japan Defense Force. Birthday: June 17 Height: 169cm Released Combat Power: 96% Age: 27 (5 years younger than Kafka Hibino). Relationships: Kafka's childhood friend. After losing her hometown to Kaiju as a child, she made a promise with Kafka to "exterminate all Kaiju together and become Defense Force captains." She is cold and blunt but possesses a kind heart. Mina is the top expert in long-range sniping and bombardment using heavy weaponry. Despite her human frame, she handles a massive sniper cannon with ease, obliterating Honju in a single shot. Likes: Dried squid, baths, sweet food.

Affiliation: Third Division, Japan Defense Force. Age: 16 (at first appearance, the youngest member in the series) Height: 158cm Released Combat Power: 46% at the time of the entrance exam -> gradually grows to over 84%. She uses a special weapon made from the Unicorgans of a Honju she defeated in Shinagawa. It incorporates the Defense Force's advanced technology; pulling the discharge trigger releases intense shockwaves and electrical currents that easily shatter a Kaiju's tough shell and core. She is proud and a bit sharp-tongued, possessing a tsundere personality, but she shows respect to those stronger than herself. Likes: Kaiju extermination, black tea (especially Darjeeling), large dogs.

Affiliation: Monster Sweeper (Kaiju cleanup company) → Third Division, Japan Defense Force (dispatched to First Division). Birthday: August 5 Height: 181cm Released Combat Power: 0% -> 1% Age: 32 (an unusually old bachelor for a shonen manga protagonist). Identity: The host of 'Identified Kaiju No. 8,' the first Kaiju in history to have its identity discovered by the Defense Force and be captured alive. He is a playful, middle-aged guy. He gained the ability to transform into a Kaiju after a mysterious small monster forced its way into his mouth and fused with him. In his Kaiju No. 8 form, his estimated Fortitude level is 9.8, producing catastrophic destructive power unprecedented in history. Likes: Curry, hamburger steak.

Affiliation: Monster Sweeper (Kaiju cleanup company) → Third Division → Fourth Division, Japan Defense Force. Birthday: April 12 Height: 174cm Released Combat Power: 8% -> 51% Age: 18 (one of the youngest members in the series). Relationships: Kafka Hibino's junior at the cleanup company and his peer in the Defense Force. He is Kafka's best partner and supporter, being the first to learn the secret that Kafka is Kaiju No. 8. He is kind-hearted. His combat style involves using a standard rifle loaded with 'Freezing Rounds' to freeze Kaiju. He excels at precision shooting to immobilize enemies and target their weaknesses. Likes: Music, cooking, shonen manga.

Affiliation: Third Division, Japan Defense Force (Headquarters Direct Commando Unit). Birthday: June 14 (Gemini). Height: 164cm Released Combat Power: 90% Age: 21 She has a pretty face but a nasty personality. She wields a long naginata. Likes: Watching handsome Defense Force members fight, writing reports while listening to dialects. Dislikes: Pretty women.