Gien Bunchou, alias En'ya, is a black-haired warrior marked by white streaks on her right side and a tomboyish attitude. Apprenticed to Gengan in her youth, she once followed his doctrine forbidding needless violence. This resolve fractured after a clash with bandits forced her to kill in self-defense, prompting Gengan to seal her sword within its scabbard using a paper string to curb her impulsivity. She later shattered this restraint during another conflict, severing ties with her mentor but claiming his weapon as her own.

Her allegiance later shifts to Ryuubi, spurred by Ryuubi’s uncanny resemblance to Gien’s late sister. This bond ignites fierce protectiveness, though her blunt communication style frequently sparks clashes. Early interactions with Kazuto brim with hostility, viewing him as a disruptor, until Batai’s tickle-trap prank compels her to acknowledge hidden vulnerabilities, slowly mellowing her demeanor.

Her arc spans multiple narratives. In *Shin Koihime†Musou*’s Shoku Route, she evolves from Kazuto’s adversary to a trusted comrade, even shielding him in combat. By *Moeshouden*, she confesses romantic feelings for him yet remains quick to anger over his inadvertent public mishaps. Design inconsistencies surface across adaptations—unzipped shorts in visual novels contrast with a closed counterpart in anime.

Spin-offs like *Sengoku†Koihime X* briefly place her within Kensuke’s memories, aligning with her core traits. Supplementary notes include her tenth-place finish in a popularity poll and narrative parallels to her historical inspiration’s rivalry with Batai, echoing *Romance of the Three Kingdoms* themes.

Initially naive toward romance and intimacy, her understanding matures over time. Yet public displays of affection or perceived impropriety still ignite her temper, sustaining a tsundere-esque tension in her relationships.