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?
So when I learned he 
wouldn't be attending college,
Als ich hörte,
dass er nicht an die Uni geht,
Cuando me enteré
de que no iría a la universidad,
Cuando me enteré
de que no iría a la universidad,
Alors quand j’ai su
qu’il n’entrait pas à l’université,
Perciò quando sono venuta a sapere
 che non voleva iscriversi all'università,
Mas quando soube que ele
não iria para a universidade,
Поэтому, когда узнала,
что в универ он не пойдёт…