o. 6's boundary, Kou has found renewed resolve to become an exorcist like his big brother. But he doesn't expect to come face-to-face with the supernatural who disappeared not so long ago--Mitsuba! The two head off on an impromptu adventure to enjoy the city nightlife, heedless of the danger awaiting them in the dark...and in the midst of it all, Mitsuba comes out with a shocking request!