Ayano, who lost her husband when her son Susumu was in elementary school and raised him by herself, is considering remarrying her boss Miyagawa when Susumu enters college... Meanwhile, Susumu has special feelings for Ayano, and while he wishes his mother happiness, he is unable to treat Miyagawa well. One night, Susumu is led into Ayano's bedroom by the sound of her breathing. As his mother turns over in her sleep, exposing her cleavage, he gently runs his fingers over her skin.