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?
Some Grandpa from a parallel world 
probably came and input it.
Hast das vielleicht du aus einer
Parallelwelt eingetragen, Opa?
La habrá programado el abuelo
de un mundo paralelo.
La habrá programado el abuelo
de un mundo paralelo.
Ça a peut-être été enregistré
par un papy venant d’un monde parallèle ?
Magari lo ha inserito nel sistema
 un nonno venuto da un mondo parallelo?
Может, дедуля из параллельного мира
у нас гостил