A certain son's story. Tatsuo Igarashi, a son who goes to a university in Tokyo and lives alone. Due to the renovation of his house, his cousin Yasuhiro Shiomi and his aunt Yuriko Shiomi moved to his mother Igarashi's house. In other words, he lives in Tatsuo's parents' house. Tatsuo was enjoying his student life in Tokyo. And when he returns home for some reason, he is fascinated by his mother's beautiful buttocks, which he had never noticed before. It was because he was a dynamic and attractive woman's body prominence to the extent that even if he moved a little, he could imagine a woman on top posture with her mother.
