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. If she continues like this, she will catch a cold. As her son approaches to carry Mio to the bedroom, a sweet and sour smell tickles his nostrils. "What is this..." The moment he sniffs, he can 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 gropes the sweaty body hidden under the steamy clothes.