Mahoro Haruta is a manga artist whose first series became a huge bestseller. Her publisher expects her sophomore effort to be even better. There's just one problem: Mahoro has no idea what to draw next, because she plagiarized the story that skyrocketed her to stardom from a high school classmate named Yukishima, who shared a few precious months with Mahoro in the school's manga club before passing away and leaving her his notebook. When, after a strange encounter, Mahoro wakes up ten years in the past-around the time of her first meeting with Yukishima-she realizes this could be her chance to redeem herself, erase her regrets, and maybe even save Yukishima's life…