Uchida was always fascinated by the beauty of Reiko, the mother of his classmate Yuya, who looked like she didn't have a child the same age as him. One day, when he went to Yuya's house as usual, he happened to witness Reiko masturbating. Uchida quickly filmed the whole thing with his smartphone camera... Later, Uchida, who had found out Reiko's weakness, visited her while Yuya was away.