This role-play is performed by adults. Her niece, Maika, came to stay at the house of part-time worker Yamada, who only thinks about her butt. Maika-chan doesn't listen to other people's stories and just plays games all day long. Maika-chan exposes her beautiful butt defenselessly... Yamada can't hold back and buries his face in Maika's butt... At first he was surprised by the sudden act, but then he started to enjoy it and on the contrary, he asked for more, as if he were toying with the old man... From that day on, a secret relationship between the two began.