Not in the exact same way but Rurouni Kenshin (Samurai X to some) created by Nobuhiro Watsuki really did base his characters on historical figures, the most skilled and prominent sword fighters during the Bakumatsu no Douran (Japanese civil war).
Quick Historical Background
Rurouni Kenshin is set during the Meiji era, which means that the emperor’s rule had been re-established. But before that, the Bakumatsu happened. Why? Because when American Commodore Matthew Calbraith Perry and his black armada showed up and “opened” Japan to the Western world, some samurai were convinced that the shogun was too afraid to stand up against some gaijin (foreigners). They, the Ishin Shishi, sought to re-establish Imperial rule.
Sounds familiar, eh? Kenshin was part of the Ishin Shishi. Kenshin is probably a composite of several people and not just this one guy. According to some, Watsuki modeled his character after Gensai Kawakami. He also was a royalist and worked as an assassin under the Choushuu Clan. He was a hitokiri (slasher) — he was called Hitokiri Gensai after all — and that he was killed in 1871, which was eight years before the Rurouni Kenshin storyline began.
So, Kenshin, er Gensai… both of them were royalists but Watsuki himself admits that he is a big fan of the Shinsengumi. The Shinsengumi were “Kyoto defenders” and in fact, a lot of the characters were based on— or were actual— members of this group.
The Shinsen troop, although bound by rules of honor, were a rowdy bunch, which would often cause trouble wherever they went.
Going back to Commodore Perry, the arrival of gaijin enraged a lot of samurai, and they became restless to the point that they deserted their han (feudal clan). Just to show you how serious this was, deserting your han means that you were severed from it forever, returning would result in death.
A lot of these roshi (masterless samurais) converged in the capital Kyoto. The bakufu (military government headed by the shogun) decided to employ them rather than have them disrupt the peace. The Shinsengumi was one such roshi-tai (bands of samurai). They were directly under Matsudaira Katamori who was the daimyo (feudal lord) of Aizu and the protector of Kyoto. The group became sort of police troop, patrolling the streets and keeping suspected Ishin Shishi in line. Authorities had a tough time disciplining the troop which soon got a bad reputation and became feared throughout the land.
Some prominent members of the Shinsengumi became the basis for the most Rurouni Kenshin characters. Here are some of them:
Sanosuke Harada
He was the basis for Sanosuke Sagara. Although in the anime, Sanosuke was part of the Sekihoutai (anti-Shogunate band of peasants). Harada was short-tempered and loved to brawl but never neglected to look out for those who were under him. He was the captain of the 10th troop and his weapon of choice was the spear.
Souji Okita
Okita actually appeared in Rurouni Kenshin. In the OAVs, he is the young kawaii swordsman who appeared with Saitou. He was something of a prodigy, he enrolled in the dojo at age 9 and by the time he was 15, he was already an accomplished swordsman. He wielded a katana, bokken, and shinai equally well but he favored the famous sword Kikuichi Norimune, yup, the same one that Soujiro used in his last battle with Kenshin.
It is said that Soujiro was modeled after Okita (they’re both young, skilled swordsmen). Like Soujiro, Okita was cheerful but unlike him, this cheeriness was not skin-deep. In fact, his sunny disposition made him quite a popular Shinsengumi figure.
Although he is the most powerful swordsman among the troop, ironically, he died of tuberculosis at age 25.
Hajime Saitou
Yup, there really was a living, breathing Saitou. However, he didn’t look like a cockroach as you have seen in the animated one. He was left-handed and his most powerful attack was the “left-handed single thrust”, not the Gatotsu which was fictional.
The animated Saitou’s tenet, Aku. Zoku. San. (kill evil instantly), is actually the real Shinsengumi’s motto. He was really married to a lady named Tokio and he really did change his name to Gorou Fujita after the war when he was working as a policeman.
A heavy drinker (not a smoker), he died of gastric ulcer in 1915, one of the few Shinsengumi who lived long enough to see the Meiji era.
Toshizo Hijikata
It’s been said that this guy was drop-dead gorgeous. But not as handsome as his animated counterpart Aoshi, the leader of the Oniwabanshu ninjas. He was pretty much emotionless like Aoshi but this bordered on mercilessness and heartlessness. Watsuki speculates that Hijikata was such because as a leader, he had to be firm in front of his followers despite what he actually felt.
As vice-captain of the entire squad, he formulated the dreaded rules of the Shinsengumi, breaking these would mean death and he personally oversaw executions and ritual seppuku (suicide). This Demon of the Shinsengumi wielded a katana and he created the Hiratsuki technique that the fictional Saitou says his Gatotsu was based upon.
Kamo Serizawa
Now we come to whom I think is the most amusing Shinsengumi figure. Serizawa was part of the troop since the beginning and was one of the co-captains. However, he was bad-tempered and impulsive (and a little on the crazy side) and thus, wasn’t very popular. He would kill people (even his underlings) without warning.
One incident particularly was very amusing: the troop was sent to an outpost but the hosts failed to give Serizawa proper accommodation. He brushed aside their apologies and said that he would just gather some firewood to warm himself up. The problem is, he started the fire right in the center of the lodging house and the flames got so big that no one was able to sleep, afraid that a major conflagration might raze the whole town.
Can you tell who his counterpart is? Yup, Makoto Shishio. And like Shishio, he was a victim of treachery. He was executed by his fellow Shinsengumi when his rash behavior became too much of a liability. Although he was an adept swordsman, his weapon of choice was an iron fan which was about 1.12 kg in weight.