Taikutsu na hi o nigeru you ni Futari de egaita chizu no ue Machi wa mabushi sugiru kara Hoshi o keshi ni ikou ka

The song explores:

Even after you disappear, So that I never cry again — Even if it’s a lie, say “I love you.” I don’t want a second goodbye.

"Shinseki no ko to tomari dakara de na" (Meaning: "Because it's a sleepover with my relative's child..." or "With my cousin, because we're staying over...")