After her husband passed away, Haruka, who had just turned 60, lived alone with her son Wataru, who was a lazy ronin. One day, she decided to clean up her son's messy room. While doing so, she finds an incest-themed pornographic book. Haruka is angry that she didn't even study... but she gets excited when she opens the book and starts reading it seriously. Driven and wet between the legs, after a long absence, Haruka forcefully and seductively approaches her son after he comes out of the bath...