Hijikata Toshizō was the vice-commander and co-founder of the legendary Shinsengumi. A legendary figure in his own right, Hijikata was the man responsible for the extremely strict code of conduct upheld by all Shinsengumi members under penalty of seppuku, leading to his notoriety as the group's "Demon Vice-Commander." Though he barely appears in the Rurouni Kenshin series, Hijikata is confirmed to have been the inspiration behind the character Shinomori Aoshi.
He is the founding member of the Shinsengumi that wrote the Internal Regulations and developed the fighting style, including the Hirazuki technique which later became the basis of Saitō Hajime's signature move, the Gatotsu, along with serving as an inspiration for Okita Sōji to develop his own signature move the Sandanzuki. He tolerates no imperfection, but is not unreasonable. As such, he has the respect of all 40 members of the Shinsengumi. He was killed in the Battle of Hakodate during the last days of the Boshin War. His death also marked the end of the Shinsengumi.