Kaiju No. 8 follows the story of Kafka Hibino and his journey to becoming an officer for the Anti-Kaiju Defense Force while concealing his secret of harnessing the power of a Kaiju in his body. Though he fails many times, his one last chance to impress sees him barely squeak in, earning the role as Cadet with the potential of earning a full-fledged role as an Officer if he can improve his skills. Though his motivation to become an Officer is based off a promise as a child to a friend, his main goal once he lands this position is to join the side of that friend, Mina Ashiro. Mina is the captain of the Anti-Kaiju's Third Division in Kaiju No. 8, representing the division as its strongest warrior.