What happens when a girl's most sensitive area is fixed with a vibrator equipped with a timer program function, gradually increasing vibration time at intervals of one to two minutes? The initial stimulation feels insufficient, but the sensation intensifies progressively over time—5 minutes, 6 minutes, 10 minutes... How will the girl cope as she's driven to her limits? This shocking scenario captures Hiro, an 18-year-old girl with a translucent, pure complexion, experiencing SM for the first time in her life.