After taking a kihei as his Bride and overcoming the massive invasion known as the Gloaming, Kou Kaguro has finally earned some peace for himself and his friends. But as they prepare for a festival to commemorate his hard-won victory, the unthinkable happens—Kou is murdered. Over and over, endlessly... Surely there must be some mistake? And what does all this have to do with an unexpected transfer student?