HBAD-689 I'm played to serve my frustrated big-breasted, big-assed gal sister whenever I have free time. Oto Alice

Ayumu has enrolled in a prestigious school in Tokyo, but he doesn't like living with other students in the school dormitory, so he lives with his gyaru older sister who also lives in the city. However, his gyaru sister is constantly bringing various men into her room and having sex with them, which bothers Ayumu, who is a teenager with a strong curiosity about sex, and he has trouble concentrating on his studies...