Toma Hikaru attends Izumo Gakuen High School alongside familiar faces: Miyuki, his younger sister-in-law, Nanami, a friend since childhood, and Nagisa, who considers him a rival. But something stranger lurks beneath the school's surface. Toma starts having odd dreams of a lovely shrine maiden praying unclothed in a lake. He cannot place her, yet she seems familiar. The dreams also show him a peculiar room inside Izumo Gakuen. Uneasy, he resolves to slip into that room, unaware that it marks the start of a long journey. This five-episode adult OVA mixes adventure, comedy and fantasy.