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?
Would you rather be sad yourself, 
or for someone else to be sad?
Koyomi, ist es dir lieber, wenn du traurig bist
oder wenn jemand anderes traurig wird?
¿Qué prefieres, estar triste tú
o que estén tristes otros?
¿Qué prefieres, estar triste tú
o que estén tristes otros?
Koyomi,
est-ce que tu préfères être triste
Se dovessi scegliere,
 preferiresti essere triste tu
Koyomi, você prefere que você mesmo fique triste
ou que outra pessoa fique triste no seu lugar?
Ты бы предпочёл сам погрустить
или чтобы кто-нибудь другой поплакал?