Character Name / Affiliation & Role / Characteristics & Overview: Kafka Hibino: Third Division (later Special Detention). The protagonist. Aimed to become a Defense Force member while working as a professional kaiju cleaner. Has the ability to transform into a kaiju (Kaiju No. 8). Mina Ashiro: Third Division Captain. Kafka's childhood friend. A genius who became a star of the Defense Force at a young age. Wields heavy firearms. Accompanied by her white tiger, Bakko. Leno Ichikawa: Third Division Member. Kafka's junior from the cleaning company. Aimed for the Defense Force alongside Kafka. Possesses extremely high potential and undergoes rapid growth. Kikoru Shinomiya: Third Division Member. Kafka's peer. An elite girl who graduated from a foreign university early. Fights using a massive specialized axe. Soshiro Hoshina: Third Division Vice-Captain. From a lineage of kaiju slayers dating back to the Muromachi period. A master swordsman who boasts overwhelming strength in subjugating small to medium-sized kaiju. Iharu Furuhashi: Third Division Member. Kafka's peer. A hot-blooded man who feels a strong rivalry toward Leno. Has a distinctive hairstyle. Haruichi Izumo: Third Division Member. Kafka's peer. Scion of the prestigious Izumo Tech, which has produced many heroes of the Great Tokyo Subjugation. Aoi Kaguragi: Third Division Member. Kafka's peer. A former rising star of the JGSDF who transferred to the Defense Force due to his high skill. Isao Shinomiya: Director General of the Defense Force. Kikoru's father. Once hailed as the strongest in Defense Force history. Wields the weaponized remains of Kaiju No. 2 (Numbers). Gen Narumi: First Division Captain. The man who boasts the strongest anti-kaiju combat power in Japan. While overwhelming in battle, he is a severe gamer and a slob in his private life. Eiji Hasegawa: First Division Vice-Captain. Narumi's support. A hardworking man who practically holds the unit together while being jerked around by the unconventional Narumi. Plus various grunt soldiers.

Numerous in variety and quantity. Currently engaged in combat with the Japan Defense Force.