Yoshitaka Nakabayashi is a fourteen-year-old orphan who inherited an immense fortune and a large mansion following his parents' fatal accident. With no remaining relatives, this sudden wealth grants him complete financial independence and autonomy, enabling him to live unsupervised. He promptly dismisses all existing servants and recruits new live-in maids to manage the mansion and attend to his needs.

Others describe him as a pubescent boy living alone with vast wealth and no oversight. He surrounds himself with young girls in the mansion, aiming to create "his own world of desire" by compelling them to serve him. His pervasive perversion manifests in installing hidden cameras throughout the house, especially in private areas like bathrooms, to record or photograph the maids without consent. He possesses exceptional natural talent for sewing, which he directs towards designing and crafting suggestive uniforms for the maids—such as sailor suits, bunny costumes, and wedding dresses. He meticulously engineers these outfits to be as revealing as possible while barely covering essential areas, reflecting his obsession with sexualized control.

Financially manipulative, he imposes crushing debts on the maids. This is most notably seen when Izumi Sawatari accidentally breaks a vase he claims is worth 5 million yen, forcing her and her sister into indentured servitude. He routinely increases their debts through arbitrary fines or additional breakages, reinforcing their dependence. Despite his generally irredeemable conduct, hints of underlying complexity emerge later. He experiences financial ruin and hospitalization, during which subtle indications of mutual care surface between him and Izumi. In the anime adaptation, internal dialogue and actions suggest potential genuine romantic feelings for her, including a desire to marry. However, these moments are undercut by his persistent perversion, and his supposed redemption is revealed as part of an elaborate scheme orchestrated by Mitsuki to renew Izumi’s contract.

Socially isolated, he is widely disliked by classmates for flaunting his wealth and perceived arrogance. His primary interactions are with the maids, whom he subjects to daily harassment. The manga portrays him as more irredeemably perverse with minimal growth. The anime introduces ambiguous layers, such as risking his fortune to support Izumi’s ambitions, though these are frequently undermined by his actions. Across all media, his role remains that of a manipulative antagonist whose wealth enables exploitative behavior, with any potential development often negated by reversion to established traits.