Nemurenai Yoru no Tsuki

Fuente: AniList

In a thick forest full of giant trees, a boy lives modestly with his family. One day, a guardian of the moon looking like a squirrel shows up in front of the boy, saying the moon got accidentally stuck on a high tree somewhere far East. Night dominates the world as the sky stops moving with the still moon. Now, the boy and the squirrel go off on adventures into the dark forest to search and free the moon.