Honmaru Edojō is a blue-haired elementary school student initially portrayed as an outcast in his fifth-grade class at Nanno Elementary School. He faces consistent academic and athletic challenges, contributing to his low social standing and making him a frequent target of bullying by classmates like Jabao Jaba and Korekiyo Ryoguchiya. His behavior includes moments of immaturity and occasional lewdness, further alienating him from peers and townspeople.

A significant turning point occurs when his accumulated misery and negative emotions accidentally summon the young wizard Taruruto. This marks the beginning of their partnership, where Taruruto's magic—though often unreliable or short-lived—helps Honmaru navigate social hardships, confront bullies, and pursue his romantic interest in Iyona Kawai, a kind and academically gifted classmate. Despite occasional benefits, Honmaru's reliance on magic sometimes exacerbates conflicts or creates new complications.

His family environment includes Shogunnosuke Edojō, a martial arts-trained picture book artist with shared tendencies toward energetic and occasionally inappropriate behavior, and Chizuru Edojō, his supportive mother. Honmaru's personal growth becomes evident through recurring challenges, including rivalries with transfer students. Tsutomu Harako, a narcissistic newcomer, becomes a primary antagonist due to their mutual affection for Iyona, frequently provoking competitions. Later, the delinquent Zakenja twins (Neyo and Nezo) intensify Honmaru's struggles, with Nezo emerging as his ultimate rival and bully.

Throughout these conflicts, Honmaru gradually develops resilience and independence. Key moments include defending Taruruto from physical threats despite the wizard's capabilities, showcasing an emerging protective instinct. His maturation peaks during a school tournament where Taruruto's magic is publicly revealed during a match against Nezo, forcing Honmaru and classmates to rely on collective effort rather than supernatural aid. The manga concludes his arc by having him voluntarily desummon Taruruto after elementary school graduation, symbolizing a commitment to self-reliance and concluding their partnership.

Honmaru's relationships extend beyond Taruruto, including complex interactions with Rui Ijigawa, Iyona's cunning friend whose pranks mask ambiguous romantic feelings toward him. These dynamics contribute to his emotional development, shifting him from a victimized underdog to a more confident individual who confronts adversaries through determination rather than magic alone. His physical appearance includes blue hair and eyes, consistent with his child-age depiction across all media.