Mirisaeki is a 19-year-old active female college student attending a women's university in Tokyo, with a shy and introverted personality. She is unaware of her own masochistic tendencies. To earn tuition money, she decides to debut as an AV actress. During her audition, her submissive nature is discovered, leading to her debut release focusing on intense anal training. As she is thoroughly penetrated anally, she becomes enveloped in the pleasure of anal stimulation, beginning to walk a new path. For her, the anus is not merely a body part, but a reward and an entrance to new possibilities.