Sanosuke was born the son of lower samurai of Matsuyama han. While he served as Chugen in the han, he troubled other samurai and ran away from the han. In Edo, he became Shokkaku of the Shieikan dojo and joined the Roshigumi with other Shieikan pupils.
While in Kyoto, he took part in the assassination of Serizawa Kamo, Kusunoki Kojuro, and Uchiyama Hikojiro. He also participated in the Ikedaya Affair, the Sanjo Seisatsu Incident, and the Incident at Aburano Koji.
Sanosuke left the Koyochinbutai (the renamed Shinsengumi) after the Battle of Koshu-Katsunuma with Nagakura Shinpachi and formed the Seikyotai. But he suddenly left Seikyotai on the way to Aizu. (Nagakura later stated that he missed his family) When he returned to Edo, which was full of Anti-Shogunate troops, he had no way out. He joined the Shogitai and was wounded at the Battle of Ueno. He died 2 days later.
Harada Sanosuke's Sword
- Kofuzumi Okitomo 江府住興友
- Shinsengumi Taishi Den (新選組隊士伝) Gakken
- Shinsengumi Zentaishi Tettei Guide (新選組全隊士徹底ガイド) Maeda Masaki