After her only son left home, Reiko began going to the gym to enjoy her second life. - She then happens to meet her sons friend, Akira. - One day, she got injured at the gym and asked Akira to send her to her house, where she happened to have a physical relationship with Akira. - Since that day, Reiko cant forget the intense piston exchanges that were unleashed from his muscular body. - Since then, every time she meets Akira, she feels a tingling sensation in her crotch, and she begins to have unreasonable expectations.