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'?!