If Nene and Kou want to return to their own world, they have to kill "Amane Yugi" and "Sousuke Mitsuba"-or rather, the versions of them living within the canvas of Number Four's boundary. Faced with that cruel choice, Nene instead proposes a way to escape from this fake world to the boy she can't help but call "Hanako-kun." At the same time, Kou tries to win over Mitsuba as well-but just who exactly is this "Mitsuba"?