Labyrinth and Magic Gunner.Arata and Lilith return to class to find the other students asleep at their desks, victims of another breakdown phenomenon. The academy headmaster suggests that the Trinity Seven and Arata work together to investigate and deal with the phenomenon, though Mira rejects working with Arata and sets off with Akio. The headmaster pinpoints the breakdown's source underneath the school, where Yui is losing control of her magic in the presence of a demon lord candidate...