As the search for "Kaiju No. 9" disguised as a human continues, a swarm of monsters suddenly attacks the Tachikawa base, where Mina is absent! The leader of the pterosaur monsters that never swarmed was a new "giant monster" who understood human language and had intelligence. As if enjoying the battle, the monster sets its sights on the strongest member = Hoshina on the spot.

Kafka, who was finally revealed to be Kaiju No. 8 and detained, was transferred to the headquarters facility by order of Isao Shinomiya, the commander of the Japan Defense Forces. Kafka's dream of becoming a defender is crushed, and Kafka is tormented by the guilt of betraying his friends. In the midst of the transport mission, which proceeds solemnly in a tense atmosphere, Mina, who is alone with Kafka, breaks the silence.