"Rina Sakauchi" 21 years old. - She has an upright atmosphere, a strict job as a city hall worker, and an ethical view of 'sex' that she had envisioned since she was a child. - She has a "serious" atmosphere in everything she does, and she has accumulated her agonizing desires. - Her stimulation since her first experience engraves her pleasure beyond her tension and makes her lewd body tremble. - Whether she's in the car on the move or waiting in the dressing room, she has plenty of time to stimulate. - She relentlessly shoves her violent pistons into her newfound pleasure. - She leads her sexual urges, which she has suppressed for four years, to her liberation, and reveals her true nature to the extent that she negates her seriousness...