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?
parallel worlds communicated with each other.
fingen die Welten an,
miteinander zu kommunizieren.
los mundos paralelos
se comunicaron entre sí
los mundos paralelos
se comunicaron entre sí
les mondes parallèles
communiquaient entre eux,
fu necessario convertire l'intero mondo
 in dati quantistici processabili
para que os mundos paralelos consigam
entrar em contato uns com os outros,
параллельные миры начали
общаться друг с другом.