Uchida was always fascinated by the beauty of her classmate Yuya's mother, Reiko, who didn't look like she had a child of the same age. One day, when he visits Yuuya's house as usual, he happens to see Reiko masturbating. Uchida immediately took a picture of the whole story with a smartphone camera. At a later date, Uchida, who grasped Reiko's weakness, visits her Reiko, aiming for Yuya's absence.
