Jiro Yoshidayama, a student in class 2-C, sports dynamic orange hair styled spiky and upright, though his look shifts to hanging loosely in bathhouse settings or styled into pigtails, causing frequent identity mix-ups. He harbors a persistent admiration for Eri Sawachika, with recurring scenarios emphasizing his exclusive focus on her over peers. His closest bonds lie with Kentaro Nara and Ganji Nishimoto, forming a trio engaged in collaborative schemes; Nishimoto’s family-owned video store aids their ventures to collect intel on classmates. A rivalry simmers with Kenji Harima as Jiro strives to dethrone him as the class’s delinquent figurehead, sparking adversarial clashes in parody-driven plots. His narrative significance escalates in later seasons, marked by expanded story arcs. His name blends the Japanese terms for "next" and "son," paired with a surname translating to "lucky field mountain," underscoring cultural and symbolic roots.