Sekai de Ichiban Hayai Haru

A manga artist named Mahoro Haruta achieves sudden success with her first series, but faces pressure to outdo it with her next work. She struggles with creative block because she stole the original idea from a former classmate, Yukishima, who had shared it with her before dying. He left her a notebook containing his story ideas. After an unusual experience, Mahoro finds herself transported back in time to when she first met Yukishima. She sees this as an opportunity to correct her mistake, address her guilt, and possibly prevent his death.