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?
So, kids these days already know the term 
"parallel world" in elementary school.
Jetzt kennen sogar Grundschüler
¿En primaria ya saben cosas
de los mundos paralelos?
¿En primaria ya saben cosas
de los mundos paralelos?
Les écoliers de nos jours
Quindi al giorno d'oggi
Hoje em dia, até as crianças sabem
sobre o mundo paralelo, não é?
Ай меня, конечно, удивила!