Kijima-san is a policewoman routinely addressing incidents involving Atsushi Miyagawa, a fifth-grade boy with an adult's appearance. Her duties frequently require responding to public concerns when Atsushi is mistaken for a suspicious adult, particularly during interactions with his classmate Hina. These recurring incidents, happening multiple times weekly, lead to repeated encounters between Kijima-san and Atsushi.

She operates within a trio of policewomen, alongside Miura—conscious of her unmarried status—and Aono, who displays an overly enthusiastic personality. Over time, Kijima-san and her colleagues become familiar with Atsushi's unique situation. Kijima-san maintains a professional focus on resolving the misunderstandings surrounding him, establishing her as a recognizable authority figure through her consistent involvement.

Across the series, Kijima-san's role evolves from initially apprehending Atsushi to becoming an ally who helps clarify his circumstances to others. By the third season (Mi♪), she and the other policewomen function as valuable resources, actively mitigating further misunderstandings involving Atsushi. This progression shifts their relationship with the main characters from repeated interventions toward collaboration.

Kijima-san consistently fulfills her law enforcement function within the series' comedic framework, responding to concerns about Atsushi's appearance and interactions. The description provides no additional personal background, development beyond her professional role, or involvement in storylines unrelated to Atsushi's mistaken identity incidents.