Brother Yuichi, upon seeing his brother's girlfriend Mai, instantly recognizes her as a masochistic woman who loves being fucked in the throat, and plots to train her. He stares intently at Mai, treating her with an almost excessive amount of kindness. One day, Mai accidentally spills tea on herself, staining Yuichi's pants. She frantically apologizes, and Yuichi, in a teasing commanding tone, makes her wipe his crotch. The next day, when Mai comes to apologize again, Yuichi, still in a teasing commanding tone, tells her to gently stroke his cock.
