Mikuru, a member of the rhythmic gymnastics club, is known as a clean, healthy, and adorable schoolgirl in uniform. Still inexperienced in sex, she gradually begins to absorb erotic stimulation. First, she receives strict and meticulous blowjob training, her small mouth carefully servicing the cock. Saliva mixes with pre-cum as her lips and tongue wrap around the shaft, desperately taking it all in. Wriggling from the sensation, she slowly awakens to masochistic pleasure, her expression beginning to shift. In that expression, one can see her innocent heart slowly being colored by desire. Eventually, her body reacts so intensely that her underwear becomes stained. When her cotton panties are pulled aside, she lightly orgasms in an instant—an honest, pure response from a heart experiencing sexual stimulation for the first time.