TV-Series
Description
Hiroko is a third-year student at the middle school attended by Kana Minami, one of the series' protagonists. She is a recurring supporting character who appears as a member of Kana's broader circle of schoolmates, with her most notable role taking place in the Okaeri season. Physically, she is depicted as a teenage girl with brown eyes and brown hair that falls to her neck.

Hiroko is characterized by an affable and playful demeanor, often engaging with those around her in a lighthearted manner. Her most defining personality trait is an enthusiastic, almost scholarly obsession with the Banchou legend, a collection of myths and exaggerated stories surrounding a series of powerful and feared student leaders at her school. The legend originated with Haruka Minami, Kana's eldest sister, whose authoritative demeanor as a class representative earned her the nickname "Banchou" during her own time at the school. Hiroko was deeply taken by these tales as an underclassman and has since become one of the legend's most fervent collectors and advocates.

This fascination directly fuels her primary motivation within the story. Alongside Kana, Hiroko is one of the sole individuals actively working to keep the Banchou legend alive. She takes it upon herself to ensure that the school always has a sitting Banchou, often bestowing the title on unwilling candidates. She has been known to assign this mantle to her best friend Yuu, to the student Fujioka, and presumably to another student named Hitomi before them. Her dedication to this self-appointed role is a significant part of her identity, transforming her from a passive admirer of the legend into an active participant in its continuation.

In the context of the story, Hiroko frequently acts as an observer and sometimes an instigator. In the Okaeri season, she becomes interested in the romantic dynamics among her peers, specifically the one-sided affection Riko has for Fujioka, the current Banchou, who himself appears to pay more attention to Kana. Hiroko inserts herself into this situation, carrying a trademark notebook and claiming the position of an interested observer or researcher. She offers unsolicited advice to Riko, encouraging her to confess her feelings and not to appear weak. Based on her own research, she provides her opinion that Kana has no romantic intentions toward Fujioka, attempting to spur Riko into action.

Hiroko's most significant relationship is with her best friend, Yuu. The two are frequently seen together, and Hiroko's playful schemes often involve Yuu as a participant, whether she is willing or not. Yuu is often the target of Hiroko's Banchou assignments, and in a notable comedic sequence, Hiroko enlists a reluctant Yuu to stand in for Fujioka so that Riko can practice confessing her love. While Yuu maintains an air of barely tolerating Hiroko’s unique hobby, it is suggested that this irritation is merely a front in the anime adaptation. As part of her role as a helper in Riko's romantic practice, Hiroko demonstrates an ability to strategize and manipulate social situations, however clumsily, to achieve a desired outcome. Her efforts as a self-styled observer and advisor highlight her proactive nature and her desire to shape the social landscape around her according to her own interests.