Kyubei Yagyu, also known as Jyubei Yagyu, is a recurring character in Gintama. She is the heir to the Yagyu clan, a prestigious family of swordsmen who serve the Tokugawa shogunate. Born with female biological sex, Kyubei was raised from childhood as a male due to her father’s desire for a son to inherit the family’s martial legacy. As a result, Kyubei adopts a masculine appearance, speech patterns, and demeanor, and insists on being referred to with male pronouns and address terms, though her internal relationship with gender remains a complex and evolving aspect of her character.

Kyubei’s personality is stern, disciplined, and deeply proud of her family’s code of honor. She speaks in a formal, curt manner and rarely shows overt emotion. Despite this exterior, she struggles with a deep sense of isolation and confusion about her identity, having never been allowed to fully live as a woman nor feeling completely at ease as a man. Over time, Kyubei reveals a more vulnerable and awkward side, especially in situations that involve traditional feminine roles or romantic feelings. She has a strong sense of justice and loyalty, though it often clashes with the rigid expectations of her clan.

Her primary motivation throughout the series is to prove herself worthy of leading the Yagyu clan, which originally leads her into conflict with the Odd Jobs Gin-chan (Gintoki, Shinpachi, Kagura) during the Yagyu arc. Initially, she challenges them over a matter of honor involving Shinpachi’s sister Otae, but the conflict resolves into mutual respect. Afterward, Kyubei becomes a frequent ally and friend to the main cast, often joining battles against larger threats such as the Benizakura incident or the Shinsengumi’s internal conflicts. Her role shifts from antagonist to a trusted supporting figure, representing the old-school samurai code adapting to a more chaotic and modern world.

Kyubei’s key relationships include a close friendship with Otae Shimura, whom she initially kidnaps to preserve her family’s honor but later comes to admire deeply. Otae’s acceptance of Kyubei regardless of gender expression is a turning point, helping Kyubei begin to explore her feelings more openly. She develops a one-sided romantic affection toward Otae, though this is usually played for both drama and comedy. She also bonds with Shinpachi as a fellow protector of Otae, and with Gintoki as a fellow swordsman who does not judge her by gender. Her relationship with her father, Binbokusai Yagyu, is strained due to the pressure he placed on her, but eventually she earns his acknowledgment without needing to deny her own nature.

Kyubei undergoes subtle but meaningful development. Early on, she insists absolutely on being male in identity and presentation. Later, she shows moments of accepting femininity—wearing a kimono in certain circumstances, blushing at compliments about her appearance, and even admitting she would like to be “courted like a lady” by Otae. However, she never fully transitions to living as female; instead, she carves out a space between rigid gender roles. By the end of the series, Kyubei remains the heir of Yagyu, confident in her sword and her choices, having reconciled her duty to her clan with her personal sense of self.

In terms of abilities, Kyubei is an exceptionally skilled swordswoman. She wields a katana with precision and speed, trained from early childhood in the Yagyu Shinkage-ryu style. Her techniques include swift iaido strikes and powerful single cuts capable of slicing through objects and armored opponents. She is also physically robust, able to keep pace with Gintoki and other top fighters in the series. Though not superhuman like some of the more exaggerated characters, her combat ability is consistently portrayed as elite among human fighters. She also demonstrates tactical thinking and strong leadership when commanding her clan’s forces. Notably, she is not shown to rely on any gimmicks or trick weapons; her strength comes purely from rigorous training and unwavering focus.