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?
Once we leave, act naturally. 
Go about life the same as before.
Wenn wir hier rauskommen,
verhalt dich natürlich.
Cuando salgamos,
compórtate con naturalidad.
Cuando salgamos,
compórtate con naturalidad.
Garde ton naturel
en sortant d’ici, d’accord ?
Una volta usciti da qui sii naturale,
 comportati come il te stesso di sempre.
Quando você sair daqui, aja naturalmente,
como costumava ser.
Как отсюда выйдешь,
веди себя как обычно, Такасаки.