Hikaru begins his days at Izumo Gakuen accompanied by his sister-in-law Miyuki, childhood friend Nanami, and rival Nagisa. Soon his sleep is interrupted by recurring visions of a serene shrine maiden praying in a quiet lake, alongside glimpses of a hidden chamber inside the academy. Disquieted by the imagery, he slips into the school after hours to investigate the room, unaware that the act marks the start of an unexpected path.