The protagonist moves in with his older brother and sister-in-law to focus on his entrance exams. Living under the same roof, he becomes increasingly distracted by her sensual charm, unable to concentrate on studying. One day, while folding laundry, he secretly masturbates with her underwear and is caught in the act by her. Though she says, "I didn't see anything," she notices his arousal and gradually begins to change her demeanor toward him. Eventually, the protagonist pleads, "Please, I need you," exposing himself to her. Hesitant at first, she gives in to his intensity and slowly begins touching his crotch...