Oh, my name is Hiroshi. I've been dating her for half a year. Her mother, Chisato, is a single mother who has raised her daughter on her own. She is a kind, beautiful, hardworking, mature woman with a calm demeanor... But actually, I've been having sex with her mother, without her knowing... Both Chisato and I know that this kind of relationship is not good, but... we can't stop our lust and desire to reproduce...