Marina and Airi, who for so long had been reproaching their stepfather for his lasciviousness and impertinence, began to get involved in this process themselves. And while they, with their school friend, were enjoying an "adult relationship" with their father, the mother of the family, Kaeko, flashed on the scene. Now the girls and their sloppy father, have to either bring their mother up to speed, or continue their lustful adventures, in secret from their mother.