Ryo is staying at his aunt's house until his uncle finishes his long business trip. It's close to his workplace, and on top of that, it's like a dream to be able to live alone with the aunt he admires. However, his aunt is married. She's someone he shouldn't get involved with. Ryo, who is trying to release his lust that he can't express to her, uses her underwear, but unfortunately he runs into his aunt. Instead of getting scolded, she says to him, "You're a naughty girl who plays alone."