愛が死ぬのは君のせい

Aio once confessed to her childhood friend Isumi, but for some reason she cannot remember his reply. She asks him to meet her again at their old secret base so she can confess once more. What she sees there is so strange that she can hardly believe it. When Isumi appears normal again, nobody seems to notice anything unusual. Only Aio is left certain that someone else is inside him.