Saitou Hajime - See our page to the wolf here . He exists in the series both in flashbacks to the old days and in the current era of the main storyline. Although he plays a secondary role, he is an important catalyst that drives the Kyoto arc and ties the past to Kenshin's present.
Okita Souji - The other featured member of the Shinsengumi. One of his fights with Kenshin is interrupted by Saitou, who points out Souji's illness. He is depicted as a short, cheerful man with a very youthful look, which is exaggerated by how he addresses Saitou (Saitou-sensei). In the OAV Trust/Reflection we see more of him at Ikedaya and with the rest of the Shinsengumi, but his personality is very much the same. Such is Okita's popularity that even though he only appeared briefly, he rated high in character polls throughout the end of the manga series.
Kondou Isami - Seen only briefly in the manga and not at all in the TV series, he does get some screentime in the Trust/Reflection but he's still not a major character.
Hijikata Toshizo - Like Kondou only really seen in the OAV, he is seen addressing the Shinsengumi prior to the Ikedaya raid and in making plans beforehand.
Harada Sanosuke, Takeda Kanryusai, Yamasaki Susumu, Inoue Genzaburou , Shimada Kai and another member identified as "Eikura" are also in a "group" shot in the 7th volume of the manga when Kenshin talks about the Shinsengumi. The same image was done for the artbook by the anime staff with Shimada left out.
It can also be speculated that two of the Shinsengumi seen in volume 20, chapter 170 leaving the Ikedaya raid could be Nagakura Shinpachi and Toudou Heisuke. The man on the far left side has a bandaged hand, which matches up to the injury Nagakura received at that battle, just as a character on the right has a head injury, again, matching with what is known about what happened to Toudou that night. A wink to Shinsengumi fans in the know? *grins*
Nagakura Shinpachi - Other than a possible cameo in volume 20, the captain of the 2nd unit is mostly notable for his absence, especially as Kenshin says in volume 7 that Nagakura, along with Okita and Saitou, was "astonishing". Historically, he lived to through to the Meiji era and lived in Hokkaido, working as a prison guard. It is known that at one time that Watsuki did not intend to end RK at volume 28 at the end of the Jinchuu arc, but to continue on with the "Hokkaido arc", which would have been a rich setting for further adventures. Seta Soujirou was said to be wandering north, Fuji was there working on railroads and Anji was in a prison... in Hokkaido! Was the stage being set at the end of the Kyoto arc with putting some of the characters there? Was there a connection to the prison where Anji was and the one where Nagakura worked? Is this why in the "Kaiden" story Saitou was said to be in Hokkaido? It's only fangirl speculation... but one can always wonder what Watsuki had in mind...
Udou Jin'e aka Kurogasa - Original Character - A former Hitokiri for the Shinsengumi, Jin'eh was so bloodthirsty that he turned on his own comrades in the Shinsengumi. He lived to the Meiji era, killing politicians and those in power, until he was stopped by Kenshin. Watsuki's notes talk of a similarity to a version of Serizawa Kamo from an unnamed, older Shinsengumi manga. " If you by chance happen to already have known this, then you have passed beyond the realm of mere Shinsengumi otakudom. You, my friend, are a Shinsengumi master." Yet the true meaning of Jin'e was to be someone who was at one time similar to Kenshin but was now his total opposite.
Character Comparisons: Shinsengumi as Rurouni Kenshin Characters
Rurouni Kenshin mangaka Watsuki Nobuhiro used a variety of influences in creating his characters, and in his freetalks he credits a number of sources - video games, American comics, and history. However, he gives the most credit to various historical novels for shaping his idea of the Shinsengumi and inspiring his original characters. He used some character "motifs" twice - once as a Shinsengumi character, and again for some of his most famous characters. Please note that this will contain spoilers for the Kyoto and Jinchuu arc storylines.
Even visually he echoes one character to the other, as seen in the comparison, below:
Sagara Sanosuke and Harada Sanosuke - According to his freetalk on Sano, he liked Harada, and again drew from Moeyo Ken - Harada was a fighter who wielded a spear instead of a sword, and described as rough-mannered and short-tempered, probably due to his background, but that he was also seen as a "big brother" character. In Moeyo Ken Harada was a large guy but Watsuki had a design already in mind - so this Harada, like Sano, is a tall, slender but muscled man.
Watsuki also mentions the rumor that Harada lived after the way and eventually went to China and beyond. This is echoed in Sano's fate at the end of the RK series - wanted for various infractions by the police, Sano jumps a ship and leaves for parts unknown. In the Kaiden graphic novel which features a short story about the RK cast five years after the end of Jinchuu, the gang receives a letter from Sano - and he's in Mongolia after seeing the world.
Shinomori Aoshi and Hijikata Toshizo - Watsuki speaks of two versions of Aoshi that are popular in Shinsengumi fiction: the first, see in Moeyo Ken (and the one Watsuki prefers) is a true fighter who will continue until his death. Then there's another version, who hides his true self for the sake of the Shinsengumi and behind his stern warrior facade - this is the version of Hijikata that was the inspiration for Aoshi Shinomori. Aoshi's coldness, especially after the death of the Oniwabanshuu at Kanryu's mansion, culminating in his attack on his former mentor Okina, is that of a man keeping incredible pain and guilt. He becomes obsessed with the idea of proving himself in the name of the Oniwabanshuu, who were unable to fight - had Hijikata not died in Hokkaido and survived into the Meiji, would he be carrying a similar obsession into an era where the great battles were past?
In the Jinchuu arc we see a much more calm Aoshi, who, though his defeat at the hands of Kenshin and his time meditating and remembering those who care for him, seems closer to the first Hijikata. He's the only one who remains composed after Kaoru's death to look at it look at it in a logical manner yet also ruthless enough to do something that horrifies the others - exhuming Kaoru's grave and cutting her open to prove his hunch that it was a hoax.
Seta Soujirou and Okita Souji - In this case the names mirror each other - Soujirou was Okita's name during childhood, when he changed it to Souji, and Watsuki states in his freetalks that Soujirou's model was Okita. Like with Hijikata there are "versions" of Okita used in novels, etc, on this he said, " Watsuki has used Okita as portrayed by [well-known historical novelist] Shiba Ryotaro, but (this time) it's not the Okita of Shiba's 'Moeyo Ken (Burn, O Sword),' but Okita of 'Shinsengumi Keppuroku (Record of Shinsengumi Bloodshed)' he's using... and that Okita has lost an important part of his human heart, making him emotionless and pretty scary. Some Shinsengumi fans are upset that a character modeled upon Okita is appearing as a villain, but since it's the 'Keppuroku' Okita that's the model, I believe it works well, and helps to make Seta a strong antagonist."
Soujirou can be seen as a "dark" version of Okita. Two young boys with instinctive sword skills, taken under the wing of two different guardians with different results in the process. Where Okita came under the care of Kondou Isami at the Sheikan dojo in Edo (Tokyo), Soujirou lived with an abusive family until Shishio Makoto came into his life. It was then Soujirou finally snapped, killed his family and decided to follow Shishio. Okita came to protect Kyoto during the Bakumatsu; Soujirou learned by the twisted logic of Shishio and by blindly follow him, he was able to "shut off" all of the emotions that could case him pain - until Kenshin was able to crack the facade of the smiling killer.
Takeda Kanryu and Takeda Kanryusai - The inspiration behind the mastermind behind the opium ring was 5th unit captain, Takeda Kanryuusai. " A man who studied Koshu-ryu war theory, Takeda Kanryusai was a rare Shinsengumi intellectual. His personality, though, was bad - kissing up to superiors, being mean and sneaky to subordinates. Basically, he was jumping on the Shinsengumi bandwagon, and once the outlook started to turn grim, he tried to defect to Satsuma Prefecture but was found out. He was disciplined... and that was the end of him. " Different from other Shinsengumi "villains" who had strong beliefs that they took to their death, Watsuki calls Kanryusai a "sincere fool".
The idea of taking this motif and applying it to the Meiji era - getting a man who valued money and imported things - drugs and weapons - to build up his fortune. A coward in the end who tried to use his new wealth to buy his safety but with men like Aoshi and Kenshin who held to the "old" values - they would not be swayed so easily.
Shishio Makoto and Serizawa Kamo - One of the many ideas that Watsuki used for Serizawa was that of Serizawa Kamo: "I decided that he would enjoy at the same time and conquering, thereby making him a destructive being - kind of like Serizawa Kamo of the Shinsengumi." He added this to a character from the video game "Samurai Spirits". While not as direct as the other three (and the pre-burnt Shishio's visualization is based on that same video game character, not a version of Serizawa), it shows how much Watsuki - even as he dismisses himself as a poor history student - turned to the pop culture side of the Shinsengumi to not only create a new universe for them but also of rich, complex characters that almost play a "what if" to the popular stories and legends.