One day, Masaru happened to come home early from school and witnessed his mother, Hisae, masturbating enthusiastically in the bathroom. Seeing his mother wet with desire, Masaru became so excited that he started groping himself in the living room, using his mother as a masturbation aid. As Masaru was engrossed in masturbating, his mother returned home and saw his bare, erect cock. Masaru panicked, but for some reason his mother's eyes were entranced as she stared at his rock hard cock... Then his mother did something unexpected that betrayed Masaru's expectations...