Shinomori Aoshi was raised as a ninja of the Oniwabanshuu, an organization that served the Shogunate government during the Edo period. He played a significant role in raising Makimachi Misao from childhood as part of the Oniwabanshuu.
After the revolution, some members of the Oniwabanshuu struggled to adapt to life in the Meiji era. Consequently, Aoshi and these members worked for Takeda Kanryuu, a corrupt and power-hungry businessman. Aoshi's subordinates included Beshimi, skilled with darts and poison; Hyotoko, known as "Fire Man" for his ability to breathe fire using flint-and-steel teeth; Hannya, a martial artist and ninjutsu practitioner who was also Aoshi's student; and Shikijou, the group's muscle.
Aoshi is often seen as an enigma, rarely showing emotions whether in or out of battle. Initially, he fought using a single kodachi alongside his martial arts skills. However, after his defeat at Kenshin's hands at Kanryu's mansion, Aoshi became consumed by the desire for revenge against Kenshin, driven by the deaths of his comrades. Upon his next appearance, he wielded dual kodachi and appeared to have completely suppressed his emotions to achieve this goal.
Their final confrontation took place at Shishio Makoto's mansion. During this battle, Aoshi realized his mistakes and began to shift towards becoming an ally of Kenshin.
