Koyomi doesn't know which world he's actually from, and neither do you until the very end, which means you're grieving a relationship that might not have ever existed in his timeline. The film asks the cruelest question: if she's from a world where you loved each other, and you have no memory of it, does that love count? A young man trying to figure out if he's the imposter in someone else's story, watching someone choose him anyway.

Koyomi Takasaki lives with his mother after his parents' divorce and enrolls at a local college prep school. Between the study-focused atmosphere and his own social awkwardness, he fails to make any friends. Then his classmate Kazune Takigawa approaches him with a claim: she has come from World Line 85, an alternate world where she and Koyomi are lovers. In a society where people routinely shift between slightly different parallel worlds, Koyomi is left to wonder whether he might be the one who comes from elsewhere. The film is a sci-fi romance adapted from a novel by Otono Yomoji, and it was released at the same time as Kimi o Aishita Hitori no Boku e.