Yuno and her husband came back to her parents' house on her father's birthday. Her older sister and her husband came later. The whole family was having a good time, but her older sister's husband, Akira, was different. Yuno let her guard down next to him, showing her underwear through the gap in her skirt and cleavage, which excited Akira. Then, when Yuno's husband had to leave for work suddenly, Akira sneaked into Yuno's bedroom... And once he made a mistake, Akira's actions became bolder, and he began to seek Yuno even when his family was right next to him...