The pungent scent of his mother’s sweat when she comes home from work makes her son lose control.

Mio, a mother who started working part-time to earn money for her son's tuition, has been falling asleep on the sofa more and more often. If she continues like this, she'll catch a cold. As her son approaches to carry Mio to the bedroom, a sweet and sour smell tickles his nostrils. "What is this..." he says. The moment he smells it, he can visibly feel his body getting hot. He wants to smell a stronger scent. Driven by an impulse, the son searches for the source of the scent and begins groping the sweaty body hidden under the stuffy clothes.