Kota, who has come to visit his childhood friend Aikawa's house for the first time in a long time, witnesses Aikawa's mother, Saki, masturbating by chance. He never imagined that Saki, whom he had admired for a long time, was such an erotic person... Fascinated by the alluring scene, Kota points his smartphone at Saki. And the moment he presses the shutter, he feels a dark desire begin to grow inside him. If he shows this photo to Saki, she might let him do it...