In the story, Kaoru is the instructor of a kendo school in Tokyo called Kamiya Kasshin-ryū. All of its students leave when a large number of people are killed by someone claiming to be the "Hitokiri Battōsai (斬り抜刀斎?) from the Kamiya Kasshin-ryū", damaging her school's reputation. Kaoru is saved from this murderous impostor by the real Hitokiri Battōsai, Himura Kenshin, now a wanderer who has sworn to stop killing.
Kaoru invites Kenshin to stay at her dojo as she notes that he is a gentle person instead of a hitokiri. As the series continues, Kaoru develops strong romantic feelings for Kenshin, who is constantly haunted by his past deeds and believes he does not deserve happiness. Kaoru also appears in the featured movie of the series, as well as other media relating to the franchise, including a plethora of electronic games and a series of OVAs. Her name means fragrance.
Creation and conception
Watsuki said that he used "no specific model" and "no specific motif" when designing Kaoru. He said that if he had to name one model, he would point to Chiba Sanako of Ryōma no Koibito. He wished to include the "commanding" quality from Sasaki Mifuyu (佐々木 三冬?) ofShōtarō Ikenami's Kenkaku Shōbai (JA). According to Watsuki, Kaoru became a "plain, regular girl" despite the "commanding" quality. By the compilation of Volume 1 in Japan he believed that the character model worked and stated that many female readers of Rurouni Kenshinidentified with Kaoru. He had not decided at the time on whether Kaoru should be Kenshin's love interest. Watsuki wished that he could design Kaoru "more cutely" and to be "more fashionable" but decided to tone down those qualities as he felt that she needed to express "down-to-earth" and financially "poor" characteristics as well. Watsuki described her ponytail hairstyle as "de rigueur" for a girl who practices kendo. Watsuki says that he enjoys drawing Kaoru and that filling in her hair is "sometimes a pain."  At the end of Rurouni Kenshin Kaoru gets a new hairstyle. Watsuki felt that Kaoru would not look like herself without her ponytail, but that her original hair style did not appear like what a mother would wear, so he created a variation for the ending. When some female readers told Watsuki that they could not decide whether Kaoru exhibited strength or weakness as a fighter, Watsuki responded by saying that Kaoru is "quite independent for her age" and could easily "hold her own" against many dojo masters in town, making her a national-level champion at least, although even this level appeared weak compared to Kenshin and Sagara Sanosuke.
Kaoru is the instructor of the Kamiya Kasshin-ryū fighting school. She inherited the fighting style and a small dojo from her late father, Kamiya Koshijirō(神谷 越路郎?), who developed the style before he was drafted into and killed during the Seinan War. At the beginning of the story, she runs the school by herself but has no students; she seems likely to lose the dojo until Kenshin appears and helps her. She is independent, possessive, compassionate, courageous, feisty, strong-willed, and a great fighter—with occasional mood swings. Kaoru is also known for her bad cooking (disliked by her friends and family) and her ability to see the good in others. Though she is short-tempered and possessive, Kaoru is very selfless.
She falls in love with Himura Kenshin from the beginning of the series, and continues to love him even after learning of his past crimes. One of Kaoru's biggest fears is that Kenshin might someday return to wandering, leaving her to be alone again. She gets jealous whenever another girl is also interested in Kenshin, such as Takani Megumi with whom she often argues but ultimately admires by the end of the manga. In the story, Kaoru is often compared to a tanuki (raccoon dog).
Although she often squabbles with her student Myōjin Yahiko, they care about each other and Kaoru sees him as the successor of the dojo. She is considered naïve to be so trusting, but she has the maturity to handle the consequences. Kaoru's beliefs are held strongly and proudly, almost stubbornly, particularly her father's ideal of katsujin-ken ("swords that give life"): swordsmanship should be used not to kill, but to protect. This belief is a slap in the face to many swordsmen, who advocate that a sword is only for "mastery and death". Himura Kenshin, however, feels that her beliefs should become reality.
Kaoru is a practitioner of the Kamiya Kasshin-ryū (神谷活心流?). Her primary weapon is a wooden bokken. A bokken is generally considered to be a more advanced weapon in kendopractice and can deal severe damage, and is likely reserved within the style for its masters and advanced students.
As a teacher of the Kamiya Kasshin-ryū, Kaoru mastered the successions techniques. In the first one, Hadome, Kaoru crosses her arms over her head and traps the blade of an attacker between the backs of her hands, retaining the grip of on her own sword. If properly used, this can be chained into Hawatari, Kamiya Kasshin-ryū's offensive succession technique. It is a counter-attack and can only be performed after a successful use of the Hadome technique. From the Hadome position, Kaoru twists her wrists, wrenching away the trapped sword and disarming the attacker.
Techniques of this style also are meant to be performed with the weapon broken. With Tsuka no Gedan: Hiza Hishigi (Handle Attack, Knee Crush?) Kaoru dive-lunges at her opponent's knees, bringing the hilt against their knee. She uses this attack to defeat Honjō Kamatari.
The series starts with a confrontation between Kaoru and Himura Kenshin. After some initial scuffles, Kaoru allows Kenshin to stay in her dojo as a guest. Her obvious feelings toward Kenshin are noticed even by his enemies, who use Kaoru as a chink in his armor. In the Kyoto Arc, Kenshin gives an emotional farewell to Kaoru before leaving for Kyoto. After Kenshin says goodbye to her and leaves, Kaoru falls into a deep depression, but is soon given the courage to go to Kyoto in order to see Kenshin after a more than irritated Megumi gives her a pep talk.
In the Jinchū Arc (manga and OVA only), Yukishiro Enishi, the revenge-obsessed younger brother of Yukishiro Tomoe, sets off to punish Kenshin for Tomoe's death. Enishi says that his goal is not to kill Kenshin, but to make him suffer by killing the person most important to him: Kaoru. However, Enishi actually kidnaps Kaoru and leaves behind a perfect replica of her murdered body. Thinking that he again failed to save the one who was most important to him, Kenshin flees to the Fallen Village and falls into a catatonic state of depression. Upon finding out that Kaoru is not dead, Kenshin recovers and goes with the group to rescue her from Enishi. She and Kenshin eventually marry and have a son named Himura Kenji.
Appearances in other mediaEdit
In Samurai X: Reflection, Kenshin and Kaoru are married, but he decides to wander again, returning to her every couple of years because he still feels the need to help others. Kaoru allows him to go, promising to welcome him home with a smile and their child. Kenshin eventually becomes ravaged by an unknown disease; to share his pain, Kaoru convinces Kenshin to share his disease with her through sexual intercourse. Kenshin then leaves to assist in the First Sino-Japanese War as he had promised the Meiji Government, not fighting and killing, but instead helping people. When he returns to Japan after a prolonged absence and they finally meet again, Kenshin collapses into her arms as he clutches her to him. Kaoru notices Kenshin's scar has faded away, signifying his death.
In the original, "pilot" issue of Rurouni: Meiji Swordsman Romantic Story, first published in 1992, Kaoru is the sister of Megumi and Yahiko. As the unrefined brainchild of artist Nobuhiro Watsuki, many of the story's details changed during the transition to serialized, mainstream manga.
Kaoru has been highly popular with the Rurouni Kenshin reader base, placing between fourth and fifth in every popularity poll. Watsuki describes Tomo Sakurai's CD drama voice as "not too airhead-y," "not too high," and "not too low."  Merchandise based on Kaoru has also been released, including plushes, keychains, and sweat bands. In an interview with Miki Fujitani, who is the seiyū for Kaoru, comments that in the OVAs series Kaoru is a brave woman totally different from her original version.
Several publications for manga, anime, video games, and other media have good response on Kaoru's character. When T.H.E.M. Anime Reviews writer Carlos Ross gave nicknames to the characters of Rurouni Kenshin he called Kaoru "a spirited girl". Megan Lavey from Mania Entertainment says that the manga version of Kaoru is "a lot wiser" than the anime version. In About.com "Top 8 Anime Love Stories", Kaoru and Kenshin's relationship ranked 8th with Katherine Luther noting it a "classic romance."
Kaoru's character in the Reflection OVA series received many negative responses. Efrain Diaz, Jr. from IGN comments that some of Kenshin and Kaoru's private moments in Reflectionare touching, and some are depressing. Anime News Network's Mike Crandol comments that Kaoru is the least successful visual character redesign in the Reflection OVA in contrast to the manga version's "distinctive girlish charm", and that "the creators tried too hard to make her look like Tomoe."is an assistant master of the Kamiya Kasshin style. She is also a kind, caring (albeit short-tempered), pretty girl who cannot cook. Her friends are very important to her, since she has no family. Her dojo is pretty much the big hangout for most of the characters. She pretty much brings in the money by giving lessons at other places. Because of this, the Kamiya Dojo is often in need of money. However, Kaoru is very optimistic, and doesn't let anything get her down. Kaoru cares a lot about Kenshin, and several times in the series, it suggests that she loves him. She gets jealous whenever Megumi flirts with him, and worries about him whenever he goes off to fight. Whenever he leaves, she'll follow him. Where he is, Kaoru is somewhere close by.