My niece, Nanami-chan, came to stay at Yamada's house, a freeter who only thinks about her butt. Nanami-chan doesn't listen to what other people say, she just plays games all day long. Nanami who exposes her beautiful butt defenselessly... Yamada can't stand it and buries his face in Nanami's butt... Although I was surprised at the sudden act at first, it became fun from the middle and on the contrary I asked for more and more as if playing with my uncle. From that day on, the secret relationship between the two began.