Teenager Kazumi awakens after a kidnapping with almost no memory of her life before it. When two girls named Umika and Kaoru find her, they insist they are her best friends and roommates, but Kazumi cannot remember either of them. Returning home only deepens the mystery as strange powers and dangerous incidents suggest that her forgotten life was tied to magical girls. With Umika and Kaoru beside her, Kazumi begins reconstructing who she was and why the ordinary life she cannot remember was anything but ordinary.