Seijirou Kanmuri, a sharp-eyed male with black hair meticulously styled to obscure the right side of his face and eye, favors crisp formal attire. His bond with a fellow otaku thrives on friction, marked by impassioned clashes over anime, games, and otaku subcultures. Though outwardly composed, he wields a stubbornly skeptical nature, dismissing media fantastical elements unless they conform to rigid logic.

As president of Takasago-ya, a company pioneering advanced figurines, he fixates on the enigma of sentient figures. Driven by curiosity, he dissects their origins and capabilities, strategically provoking scenarios to observe their responses. He needles debates about niche anime heroines to measure emotional triggers and covertly introduces autonomous figures like Bellnoa into his friend’s environment, probing behavioral patterns.

His relationships teeter between alliance and competition, intellect often eclipsing emotional ties. While equally devoted to 2D characters, his passion manifests as clinical analysis, merging fandom with a compulsion to unravel the engineering behind sentience. This duality casts him as both ally and adversary, shifting roles to suit his investigative agenda.

The name Seijirou—woven from characters meaning "become," "next," and "son"—paired with "Kanmuri" ("crown" or "cap"), echoes themes of legacy and authority. His past remains unexamined, narrative emphasis resting on his entanglement with sentient figurines and the cerebral rivalry defining his pursuits.