君を愛したひとりの僕へ

Koyomi Hidaka grows up around his father's research into Imaginary Science, the study of parallel worlds a person can slip between through a Parallel Shift. When their parents plan to marry, Koyomi and Shiori Sato find their growing feelings blocked by the prospect of becoming step-siblings. Rather than give that up, the two decide to shift into a world where they were never made into family. The film opened alongside a companion, To Every You I've Loved Before, which follows the same choice from the opposite direction.