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?
We lived there with my grandfather, 
my grandmother, and a big dog.
Im Haus waren Großvater,
Großmutter und ein großer Hund.
Allí vivían mis abuelos
y un perro grande.
Allí vivían mis abuelos
y un perro grande.
Mes grands-parents y habitaient
avec leur gros chien.
A casa c'erano il nonno e la nonna.
Na casa, moravam meus avós e
um cachorro de porte grande.