Koumajou Densetsu II: Stranger's Requiem

Some time after the events of the first game, Sakuya Izayoi returns from an errand for Remilia Scarlet involving a book, only to find the mansion empty. It isn't long before Yukari Yakumo appears and gives Sakuya a clue about where Remilia is and vanishes soon after. She sets out to look into Yukari's clue along the ruins of the castle long since destroyed, only to find it rebuilt.