After losing his father, the son invited his mother to a hot spring inn to thank her for raising him alone. Seeing her smile as she soaked in the hot springs and enjoyed delicious meals brought him some comfort. However, that night, the son began giving his mother a massage, touching her with deep affection. Then, she revealed she was currently dating another man, shocking him beyond belief. As she fell asleep late at night, the son lay awake, haunted by memories of their time together, his chest tightening with emotion. Overcome by the desire to keep her as his alone rather than lose her, he pulled back her futon and began caressing her body. Awakened and startled by her son's actions, she could not resist his strength, eventually accepting him and reaching climax herself.