College student Mio gradually realizes the masochistic desires awakening within her, yet struggles to accept them. Once a diligent, kind girl devoted to her studies and club activities, she now finds pleasure in being dominated, treated as a "slave," and establishing a master-servant relationship. Though this dynamic brings inner conflict and anxiety, she keeps returning, craving more discipline. The earnest Mio everyone knew has transformed into a depraved, masochistic woman who mindlessly sucks her master's cock and gets wet without any romantic feelings involved. After class, she appears normal among her peers, but behind closed doors, she eagerly takes her master's unwashed cock into her mouth, chasing pleasure. Upon arriving at a hotel, lifting her skirt reveals a strong feminine musk—her pussy already soaked before even seeing her master. When a vibrator is thrust inside, she wears a satisfied expression, moving her hips on her own. Forced into a slightly tight school swimsuit, her body shows lewd indentations, where shame and masochistic instinct collide. She takes her master's cock into her mouth and begins sucking. He whispers, "Your sensitivity's gotten better lately, hasn't it?" as he drools into her mouth—an act that further deepens her training. The taste and smell of saliva now instantly wet her pussy. At that moment, feeling utterly under her master's control, she wonders if she'll ever be able to have a normal relationship again. She swallows his thick cum, draining every last drop. Before the next "session," Mio showers in anticipation, her pussy already drenched, oozing fluids when she inserts a finger. Her lower body twitches in response to her master's finger movements, her vagina actively pulsing. When an electric massager is applied, her clitoris swells to the size of a bean. She cries out loudly, shuddering in small spasms. Whether from approaching orgasm or temporary loss of consciousness, she remains in a dazed state for a while. She repeatedly entwines her tongue with her master's, greedily swallowing saliva, pooling it in her mouth before swallowing it down. Her mouth, filled with both their spit, is then stuffed with his cock, which she desperately tries to fit into her small mouth. Finally, she guides his cock into her own pussy for bareback penetration. The façade of the serious college girl has completely vanished—her nipples hard and erect, reacting intensely to her master's touch. Her vaginal entrance sealed by his cock, she emits sensual moans. Trained into submission by an older man's cock, Mio can no longer be satisfied by ordinary sex.