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?
Apparently an unauthorized Optional Shift 
targeting Kazune-kun has been confirmed.
Auf Kazune-kun ist ein unerlaubter
Optionalsprung detektiert worden.
Se detectó un optional shift
no permitido de Kazune.
Se ha detectado un optional shift
no permitido de Kazune.
Il semblerait qu’on ait forcé
Ci hanno confermato che Kazune ha effettuato
 uno spostamento opzionale non autorizzato.
Мы обнаружили несанкционированное
спровоцированное смещение Кадзунэ…