Nitta is a first-year student at Kusai High School and the youngest member of the Teddy Bear Brigade, a group of girls who create original teddy bears and perform teddy bear‑related activities. She is described as the newest and geekiest member of the brigade. Her personality is loyal, responsible, and hard‑working, often seeking reassurance and stability. In the Enneagram system she is associated with the Loyalist type, which reflects a tendency toward caution and a desire for security. Nitta is the only side character in the series known to have a romantic partner: her boyfriend Takada. This relationship is a distinctive element of her role in the story, as most other supporting characters do not have confirmed love interests. Within the Teddy Bear Brigade she interacts closely with the wealthy and fashionable Rio, as well as with her close friends Kajii and Asada. Her motivations are primarily social: she values her place in the group and her bond with Takada. Her development is limited, but her romantic relationship sets her apart from other supporting characters. Notable abilities include her involvement in the brigade’s teddy‑bear crafting and performances.