To Me, The One Who Loved You

Following his parents' divorce, Koyomi Hidaka chooses to live with his father, who works at a prestigious institute researching parallel worlds. While visiting the laboratory, Koyomi meets Shiori Sato, the daughter of a fellow researcher, and the two children quickly fall deeply in love. Their happiness is shattered when their parents announce their engagement, which would legally make Koyomi and Shiori step-siblings. Desperate to avoid this familial fate, the young lovers attempt to jump to a parallel universe where their parents never met, but a tragic accident traps Shiori's consciousness as a phantom at a pedestrian crossing.