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?
By "Koyomi" I mean the one from that world, 
the Koyomi Takasaki of world 85.
Mit Koyomi meine ich den
Takasaki Koyomi 85 Welten entfernt.
Koyomi es el otro Koyomi Takasaki
del mundo 85.
Koyomi es el otro Koyomi Takasaki
del mundo 85.
« Koyomi », c’est le moi existant
dans le monde 85.
Con "Koyomi" intendo l'altro,
Esse "Koyomi" é o Takasaki
Koyomi do 85º mundo.
Коёми — это не я,
а мой двойник из восемьдесят пятого мира.