Sung by rosalie from anime slime 300 (Slime Taoshite 300-nen, Shiranai Uchi ni Level MAX ni Nattemashita / I’ve Been Killing Slimes for 300 Years and Maxed Out My Level ) episode 10.
Nagaku hitotsu no tokoro ni todo matteru to
Hiru made mo makkura ni kanjiru
Kurai-kurai-kurai hontou ni nani mo nai
Warai kata mo wakaranai
Shinitakute mo shine nai
sonna yoru deshita.
English Translate
when you’ve been stuck in one place for a long time.
Even the daytime seems dark.
so dark, so dark, so dark, there’s truly nothing.
I don’t even know how to laugh anymore.
Even though I want to die, I can’t.
That’s what that night was like