Katsuya is a salaryman who avoids overtime to spend his entire income on sugar dating pretty girls. While searching for a new partner, he is shocked to discover his own niece, Mifuyu, on the site. After initiating a secret relationship with her, Katsuya crosses paths with Ririka, Mifuyu's arrogant and wealthy classmate. When Ririka attempts to manipulate him for her own gain, Katsuya reveals a dominant side, turning the tables on the bully and forcing her into a compromising position.
Katsuya continues his secret relationship with his niece, Mifuyu, while turning his attention toward her arrogant bully, Ririka. By orchestrating a trap and using blackmail, the lecherous salaryman breaks Ririka's pride and forces the domineering rich girl into submission. As Mifuyu seeks more affection from her uncle, Ririka is left humiliated and socially isolated.
The salaryman continues to exploit Riri through blackmail and forced "product testing." Attempting to regain control, Riri teams up with a peer to plot a trap to punish him, but the plan backfires spectacularly. Outsmarting them both, the salaryman uses chemical stimulants and dominance to shatter Riri's defiance, leaving her completely at his mercy.
The salaryman continues to use blackmail to coerce Riri and Shirasagi into sexual acts across the school campus, from the bathrooms to the infirmary. While Riri struggles under his control, Shirasagi begins to play a dangerous game of her own, attempting to manipulate the salaryman's feelings and finances. What starts as coercion evolves into a psychological power struggle as Shirasagi strives to turn the tables and make him fall for her first.