Bizarre creatures referred to as "Unknown" appear over the coast of Tokyo Bay. Defending against them is the mission of high school students in Tokyo, Kanagawa, and Chiba who possess a supernatural power known as "World." Among them all, the head of the Tokyo school, Ichiya Suzaku, defeats Unknown with particularly overwhelming power, but Tokyo's subhead, Canaria Utara, observes his lack of teamwork with a troubled expression.

Hotaru races toward Tokyo, determined to keep her promise to never keep Maihime waiting again. Meanwhile, Maihime is increasingly overcome with exhaustion as countless Unknown bear down on her. Just then, a unique Unknown that Maihime determines to be their boss shows up.

When Suzaku and the others stormed the gate, they found themselves face-to-face with someone they never expected... one who, despite being human, doesn't fall on the same side as the world they must protect and the people they must save. Suzaku and the others are forced to question whether they're truly prepared to do what they came to do. The battle for the world will be settled here and now...