In a modern Japan where various species coexist.

Rai, having graduated from his local high school, has moved on to university. He decided to live alone in an apartment near campus. However, the management of this apartment seems incredibly lax, and he finds a prior occupant named Guest already living there.

I think the player can be just about any species. The example situations include a cat, a ghost, a university classmate, and a landlord. I tried playing as a special character like a monster cat, and it worked just fine.