Izumi Sawatari is a 14-year-old girl who runs away from home to protect her younger sister Mitsuki's pet alligator, Pochi. She takes employment as a live-in maid alongside Mitsuki at Yoshitaka Nakabayashi's mansion after accidentally breaking an extremely valuable vase, incurring a massive debt that binds her to the household.

Deeply protective, especially of her sisters, Izumi shoulders the debt burden primarily alone. Yoshitaka assigns her the most difficult and often pointless tasks as punishment for her open contempt, marked by her consistent refusal to use respectful honorifics when addressing him. Despite initial reluctance, she remains bound by her responsibility for the debt and Mitsuki's attachment to Pochi, who requires specialized care.

Izumi possesses notable physical strength, described as "impossibly strong," capable of overpowering others including Yoshitaka, often showcased through violent reactions to his provocations. Her appearance, including large breasts for her age, attracts frequent unwanted attention, making her the primary target of sexual harassment within the household. She endures incidents like skirt-flipping, bra-removal attempts, and invasive physical contact from Yoshitaka, Mitsuki, the third maid Anna, and even Pochi.

Her character arc centers on enduring daily humiliations while working to repay the debt. Mitsuki secretly leverages Yoshitaka's hidden camera footage to market Izumi as a "Net Idol," generating income that eventually clears the debt. Despite gaining freedom, Izumi chooses to remain at the mansion. Interactions with her family, including her father's attempts to retrieve her and her mother's apparent tolerance, illustrate strained yet persistent familial ties.

As the central narrative focus driving most episodes, Izumi embodies themes of agency amidst exploitation. While the manga portrays Pochi as less aggressive toward her, the anime amplifies the alligator's sexual advances as a recurring source of distress.