The story follows 20-year-old Lilly (played by Ayaka Miyoshi), who lives a seemingly carefree life in Tokyo. However, her life takes a dramatic turn when she meets a mysterious woman named Shoko (played by Fuka Koshiba), who looks identical to her. Shoko approaches Lilly and reveals that she has been sent to the past to protect her from a catastrophic event that will change her life forever.