Diving into the lingering aftertaste of a kiss as the new semester begins. And then, an autumn storm. "Good fortune often invites mischief, like clouds in the moonlight and storms among flowers"—an expression that illustrates how good things are often interrupted by trouble. Having overcome the "storm," Nanoha and Chidori have deepened their bond. However, being overly conscious of each other leads to some awkward moments between the fresh pair. As they prepare for the next event, the cultural festival... And then────── their "secret" finally...!?