Bizarre creatures referred to as Unknown appear over the coast of Tokyo Bay and must be repelled by high school students in Tokyo, Kanagawa, and Chiba.

Suzaku is teamed up with Hotaru and one of his least favorite people, Kasumi, to investigate rumors of an Unknown appearance.

After being saved by the Chiba and Kanagawa forces and beating a retreat, Suzaku is called to take responsibility for acting on his own.

The casualties caused by the Unknown's sudden attack are so severe that Suzaku loses his confidence and will to fight, so Maihime steps up to act as Tokyo's leader.