Shirojo is member of Oniwanbanshu onimitsu ninja group. In the everyday peace of daily life, he helps run the the Aoi-Ya as a professional chef of Japanese cuisine, assists Okina, and serves as Misao's caretaker. In combat, he is seen to wield brace like gauntlets that he can fire to be used as shuriken. (Source: Rurouni Kenshin Wikia)
Kurojou is member of Oniwabanshuu onimitsu ninja group. In the everyday peace of daily life, he helps run the Aoi-Ya as a PROFESSIONAL chef of Japanese cuisine, a repairman, assists Okina, and serves as Misao's caretaker. In battle, Kurojo is seen to wield a huge bo staff and bracer like gauntlets that can be thrown like shuriken. (Source: Rurouni Kenshin Wikia)
Kamatari is a member of Juppongatana who is in love with Makoto Shishio. His weapon of choice is a large scythe with an attached ball and chain, a very heavy weapon. While he appears feminine, he is in fact a male. While he is loyal and high spirited he fights in order to make up for not being as skilled as Soujiro, being less intelligent and manipulative than Hoji, Shishio's tactical adviser, and not being as beautiful as Shishio's lover Yumi. Kamatari loses in the battle of Aoi-Ya to Kaoru and Misao. According to Cho, after Shishio's defeat he becomes a spy for the Japanese government.
Based on the actual captain, Sagara S�z� (1839 - 1868) was the leader of the Sekih�tai's First Troop. Sanosuke looked up to him greatly; he was, to Sanosuke, the ideal role model. He was killed when the Meiji government purged the Sekih�tai, leading to Sanosuke's embitterment towards it. His head was placed on a platform and in a cage for all to see, it haunts Sano still to this very day. Sometime after his death, Sano took his name and became Sagara Sanosuke. Info taken from Wikipedia
Fuji is a giant, considered a freak by everyone around him. One day he was attacked and almost killed but the old man Saizuchi found him and took him in. The gentle, depressed Fuji was in an ideal state for Saizuchi to manipulate his emotions and turn him into an unbelievable fighter. Saizuchi keeps telling Fuji that he owes him for saving his life and uses that to control him. He was easily defeated by Hiko Seijūr�, though he spared his life, who unlocked his true martial artist's soul and was the first to look at Fuji as someone other than a monster. Upon capture, the Meiji government assigned him to northern Hokkaid� to develop land and act as a defending fighter during times of war. (Source: Wikipedia)