The moment Misono's nipples were first touched by an adult man, her heart was shaken. Always cheerful and full of charm, Misono struggled with her studies despite her bouncing, massive breasts, causing her grades to plummet to the point of nearly repeating a year. The real reason behind her poor performance? She was deeply addicted to "nipple masturbation," secretly teasing her sensitive nipples alone in her room. Determined to improve, she hires a private tutor, but even then, she can't suppress the tingling sensation, her eyes inevitably drawn to her tutor's huge breasts. When their feelings finally align, the tutor's fingers gently brush against Misono's nipples, initiating her first intimate experience with an adult woman.