Adapted from Maybe's manga, Tasogare Otome x Amnesia is set in Seikyou Private Academy, where the old school building is steeped in occult rumors. For 60 years, its basement has been home to Yuuko, a young woman whose death is a mystery even to herself; she remembers neither her life nor how she died. Refusing to let those missing memories fade, she takes over the Paranormal Investigations Club and starts tracing the school's Seven Mysteries for clues.
Her search becomes personal when she meets Teiichi Niiya, a first-year student who can see her and is drawn into the hidden side of the academy. Teiichi chooses to help Yuuko uncover the truth behind her existence, and their investigation soon pulls in Kirie Kanoe, Yuuko's relative, along with Momoe Okonogi, a second-year student who remains blissfully unaware of the supernatural chaos around her. As the four navigate whispered legends, empty corridors, and half-remembered fears, the club's work slowly reveals how the school's secrets are tied to Yuuko's own forgotten past.
Balancing ghost-story tension with school-life intimacy, Tasogare Otome x Amnesia blends supernatural intrigue, bittersweet romance, and melancholy mystery as it follows a bond formed between the living and the dead at Seikyou Private Academy.