Toma Hikaru transfers to Izumo Gakuen High School surrounded by familiar faces: his sister-in-law Miyuki, childhood friend Nanami, and rival Nagisa all occupy his daily life. But something stranger lurks beneath the school's surface. Night after night, Toma dreams of a mysterious shrine maiden bathing naked in a lake, praying with urgency he can't quite understand. Her identity remains frustratingly out of reach, yet her face feels known somehow. The dreams grow more vivid, pulling him deeper into confusion and curiosity. When visions of a hidden chamber within the school itself begin bleeding into his sleep, Toma's unease tips toward obsession. Against his better judgment, he decides to break into the building after hours and find this secret room for himself. What he discovers launches him into an adventure far stranger than any high school should contain, one that entangles him with supernatural forces and tests every assumption he holds about his school, his friends, and the shrine maiden who haunts his subconscious.