At a friend's house, I ended up alone with my friend's well-mannered younger sister Riku-chan and we decided to play a game together. I was taken aback by the proposal of a forfeit where the loser has to obey any command from the winner, and I ended up losing. I thought about what kind of cute order she would give, but she smiled and said, "Please get completely naked"... What? She looked so innocent, but she was actually an ultra-S type hiding under a J-system facade! She kept making erotic demands in polite language, and my hellish days of being used as a live dildo to be milked for semen began.
