Yagyuu Kyuubei (柳生 九兵衛) is the sole heir(ess) to the Yagyuu family name, being the daughter of Yagyuu Koshinori and granddaughter of Yagyuu Binbokusai. She is brought up as a male, following the code of a samurai. She is the main antagonist of the Yagyu Arc.
After Yagyuu Koshinori's wife died giving birth to Kyuubei, he never remarried and decided to raise Kyuubei as a male, to be the proper heir to Yagyuu family.
During her childhood, she became friends with Shimura Tae and her brother. During her time with Tae, she admired her strong yet feminine personality. When the debt collectors tried to harm Tae and her brother, Kyuubei tried to rescue them, though it cost her her left eye. From then on, Tae pledged to be her left eye. Kyuubei then left to train herself to be strong, using Tae as her inspiration.
- Height = 157 cm (5' 2") ; 165 cm (5' 5") (with sandals)
- Weight = 45 kg
Kyuubei dresses as a man. She has black hair in a ponytail and dark-brown eyes, with an eyepatch covering her left eye. Her weapon of choice is usually a sword. When dressing as a female, she is very attractive; complete with twin ponytails and an orange flower covering her left eye. She wears a pink kimono with short skirt and black socks covering up to her thighs. She also has large breasts despite being covered up most of the time, as seen in episode 217 when Hasegawa Taizo and Gintoki calling them "tasteful cups" when she was in a swimsuit.
Kyuubei has a bit of a cold personality, probably due to how she trained herself to become strong. However, Tae's influence is currently shaping a more softer Kyuubei, as they share more time together during their free time. She is deeply in love with Tae, and once tried to marry her. Kyuubei tends to act masculine as she was more or less raised as a boy. She also doesn't like it when men touch her, having the automatic reflex of throwing them over her shoulder whether she likes it or not.She also wishes to be a man, secretly wanting to add a man organ to her body or have plastic surgery. She is currently in conflict with being given the opportunity to become a man.
Strength & Abilities
She is a genius swordsman; surpassing average swordsmen in skills, and is able to hold herself against veteran swordsmen, like Hijikata Toushirou and Sakata Gintoki. She is famous of her lightning-fast sword strikes, and has mastered the Yagyuu Ryu sword school after going on a training journey.
- Yagyuu Binbokusai: Her grandfather.
- Yagyuu Koshinori: Her father, he insists Kyuubei to call her daddy or papa due to their status as celebrities.
Friends & Allies
- Toujou Ayumu: She is always being guarded by Toujou Ayumu, to the point of being overprotective towards her. He also tries to convince her to wear gothic lolita outfits, which cause irritation to her, blasting/beating him up because of it.
- Shimura Shinpachi: She treats Shinpachi as a friend since he is the younger brother of Tae.
- Kondou Isao: She hated him when their were first meet ( Yagyu Arc.) but in time, she began to like him. They are love rivals, but they don't argue about it. Both of them want to make Otae happy, and that purpose made them closer.
- Sarutobi Ayame: They gain a friend interaction during the kintama arc.
- Shimura Tae: She still has some affectionate feelings for Tae, though the two remained in friendly ties after the Yagyuu arc. She goes wherever Tae goes and tries things that Tae does. It has also been revealed that she actually likes Tae's cooking. She also protects Tae from the stalker Kondou Isao. After having her gender changed, she seem to become more interested in becoming Otae's 'boyfriend'.
- Sakata Gintoki: Gintoki is the only guy that made Kyuubei behave like a girl and made her nervous or blush whenever he touches her.
- Katsura Kotarou: In recent Gintama chapters, she became the target of jealousy of Katsura Kotarou, as he felt that she is recently becoming more active in the manga spotlight than him.
- Jugem Jugem: A shogun pet that is given to the Yagyuu clan.
During her introduction, she came back after years of training. She tried to take Shimura Tae hand for marriage as her fiancee, though Shimura Shinpachi and the rest opposed to it.
But after losing against Shinpachi (and the gang) in a dojo challenge, Kyuubei gave up her plan, conceding that Tae could never love her as a man. The two remained friends after the incident.
She fought along side Kagura to save Tae when she fell down in the pool of sharks
Devastated for the lost of Otae to Kondou, Kyuubei undergone a procedure to replace her female genital with a male genital. Now she searches for a new world where gender doesn't matter.
- She along with Tsukuyo and Sarutobi tried to kill Gintoki for supposedly destroying Tama and try to attack Kintoki but later changed sides to aid Gintoki.
Beam Sword Style Arc
- Yagyuu Kyuubei is based on the feudal era samurai Yagyū Jūbei Mitsuyoshi 柳生 十兵衞 三厳 who was later regarded as the best swordsman of the Yagyu Clan. There is a legend in which Jubei had only one eye and wore an eyepatch.
- Also on Date Masamune 伊達 政宗 who was outstanding tactician, he was made all the more iconic for his missing eye, and Date was often called dokuganryū (独眼竜), or the "one-eyed dragon" and his helmet was famous for having a crescent-moon, an allusion was made for both on the Group Date Arc.
- The "kyuu" in Kyubei is the word for "nine", and the "juu" in Jubei is the word for "ten"
- During the Scandal Arc, Kyuubei is the only girl who actually felt that they went too far in punishing Gintoki. She got convinced by Otose that the punishment was perfect.