Takeshi, who came to Tokyo to take the university entrance exam, decided to stay at his older brother's house in Tokyo and take the entrance exam. Her brother's wife Maria, whom she met for the first time in a while, is a gym instructor and is attractive with her toned body and G-cup breasts. Takeshi becomes lustful for his girlfriend's sister-in-law, so he thinks he can somehow have sex with her, so he buys an aphrodisiac online and drinks it in protein.