While struggling to make friends after his parents’ divorce, Koyomi Takasaki meets Kazune Takigawa, but apparently, they already have. Kazune reveals that she’s from World Line 85, an alternate universe in which she and Koyomi are lovers. But in a reality where moving between dimensions is natural, could Koyomi be the one from another world?
I love the you that saved me from 
the wild dog, and the you that didn't.
Du, der du mich vor dem Streuner gerettet hast,
und du, der du das nicht getan hast.
Al que me salvó de un perro callejero.
Al que me salvó de un perro callejero.
Celui qui m’a sauvé
d’un chien errant,
Anche quel te stesso
che mi ha salvata dal cane randagio
Aquele você que me salvou do cachorro,
И того, что спас от бродячего пса…