A slender, busty track and field girl is subjected to four days and three nights of intensive masturbation training by a middle-aged consultant's dirty penis. (ROYD-222)

Her enormous breasts, so incongruous with her youthful appearance, were irresistible, and the track and field advisor assaulted her in the locker room. Although 'Miyu' knew it was wrong, her body gradually began to crave pleasure. Even though she had a boyfriend, she couldn't believe she was becoming so aroused, her panties soaked with sweat…