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 Fours boundary. Faced with that cruel choice, Nene instead proposes a way to escape from this fake world to the boy she cant help but call Hanako-kun. At the same time, Kou tries to win over Mitsuba as well-but just who exactly is this Mitsuba?!