Rino Takanashi, a stunning 26-year-old mother with a face as angelic as her body is sinful, finds herself in a predicament. A young virgin, Hayato Tsuji, has a peculiar fetish - he wants to perform '授乳手コキ', a unique form of handjob involving lactating breasts. Rino, married with a child, is initially taken aback, but her curiosity and marital ennui lead her down a path of exploration. She discovers that Hayato's inexperienced, yet eager tongue brings her unexpected pleasure, and soon, she's guiding him, her big tits heaving, as they cross the line into taboo territory.