After receiving a call from his pregnant daughter, Yuki rushes to her and her husband's house in Tokyo. Hearing what's going on, his daughter tells him that her stepson, Junya, keeps coming on to her wherever he goes, so Yuki was called in to restrain him. Not only that, his daughter has even issued a ban on masturbating. After hearing Junya's story, Yuki feels sympathy for him and offers to give him a handjob. Once the plug is loosened, the stepson's sexual desire flows uncontrollably, slamming his hard cock into his stepmother's ripe body...