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?
That said, it's not your physical 
body that does the moving.
Aber es ist nicht der Körper,
der sich dabei physikalisch bewegt.
Aunque no es que el cuerpo
se traslade físicamente.
Aunque no es que el cuerpo
se traslade físicamente.
L’enveloppe corporelle
ne voyage pas entre ces mondes.
Comunque sia, esso non consiste
 nello spostamento fisico del corpo,
Mas não significa que vamos
nos mover fisicamente...
Но не подумайте,
физическое тело остаётся на своём месте.