Autumn events in Japan are synonymous with moon viewing, or otsukimi. Otsukimi is a very elegant festival where you present an offering to the moon and gaze at the beauty of it.
The offerings presented are rice dumplings and pampas grass. The rice dumplings are a round shape from the moon, so they are called tsukimi dango. Also, pampas grass is offered due to its similarity to rice stalks, though it appears even real rice stalks are sometimes offered as well.
The purpose of this custom is to pray for a good harvest, and it is said to have started during the Edo period. This festival is usually held on August 15th of the old calendar (Jugoya), and in 2017, Jugoya looks to be on October 4th.
Rabbits are often seen during Japanese Otsukimi celebrations. The reason behind this comes from an old folktale about how the surface of the moon resembles rice cake-pounding rabbits, and this is a tradition practiced even this very day. Well, it seems that Yuko-chan is having a good time with the otsukimi and all, but what she really wants is some rice dumplings. Guess you could say that she's half-rabbit? *chuckle*