Kotaro Satomi is a needy student who started living away from home at the start of high school. he finds a bargain accommodation - only 5,000 yen for a six-tatami mat room. But the room, "Korona-So room 106," is targeted! For various reasons, adorable invaders descend upon Kotaro one after another as soon as he moves in. Each with their own ulterior motives, the battle commences between Kotaro and the girls in a tiny six-tatami mat room.

[Source: Crunchyroll]