Mahoro is a successful manga artist whose hit series was built on ideas she took from a classmate who passed away. Now under pressure to create her next work, she is left with nothing of her own. When she suddenly wakes up ten years in the past, back to when they first met in high school, she realizes she has been given a second chance. Determined to fix her mistake, Mahoro sets out to return his story, face her guilt, and try to save his life before it is too late.