The Moon

The Moon is Princess Kaguya's original home. It is where the people of the moon reside in, but at the moment the gate to the moon is sealed off and the precious moon spring water resource is running out. The only way to save it is to place bones of dead humans into it to replenish supplies.

Location
The moon is in the sky almost every night and although it is very important in the story it's very rarely seen, only when referring to Princess Sakura or Hayate's Jutsu is it mentioned or presented.