Okita Souji was born Okita Soujirou Fujiwara no Harumasa (Okita=family name, Soujirou=given name, Fujiwara=family clan name, Harumasa=formal given name/middle name equivalent) in 1842 or 1844 from a samurai family in the Shirakawa- han’s Edo mansion. His great-grandfather was Okita Kan’emon and his grandfather was Okita Sanshiro. His father, Okita Katsujiro, died in 1845; he had two older sisters, Okita Mitsu (1833-1907) and Okita Kin (1836-1908.) In 1846, in order to marry the adopted son of the Okita family, Okita Rintarou (1826-1883), his oldest sister Okita Mitsu became an adopted daughter of Kondou Shusuke in name. Kondo Shusuke was the third master of the Tennen Rishin Ryu and Okita started training at the Shieikan with him around the age of nine (between 1850 and 1852.) By that time, Kondo Shusuke had already adopted Shimazaki Katsuta (the later Kondou Isami was enrolled in 1848 and was like a “TA” to Okita), but Hijikata Toshizou had not yet enrolled at the Tennen Rishin-ryu school (Hijikata was formally enrolled in 1859.)
Okita proved to be a prodigy and attained Menkyo Kaiden status (master of kenjutsu) at eighteen or so (Kondou Isami mastered all the techniques of Tennen Rishin-ryu only a year or two earlier.) In 1861, Okita became the Head Coach (Jukutou) at the Shieikan. Even though he was often commented to be honest, polite, and good-natured by those around him, he was also known to be a strict and quick-tempered teacher to his students.
He changed his name to Okita Souji Fujiwara no Kaneyoshi shortly before his departure to Kyoto in 1863. He soon became a founding member of the Shinsengumi and a Fukuchou Jokin (Vice-Commander’s Assistant.) Okita Rintarou, also a practitioner of the Tennen Rishin-ryu, became a commander of the Shinchougumi (the Shinsengumi’s brother league in Edo.)
Okita was one of the Shieikan members involved in the Serizawa Kamo and the Uchiyama Hikojirou assassinations in 1863.
He was one of the strongest out of the Shinsengumi, along with Saitou Hajime and Nagakura Shinpachi. His signature technique was named the Mumyo-ken or Sandanzuki, a technique that could attack one’s neck, left shoulder, and right shoulder with one strike.
It was rumored that his tuberculosis was discovered when he coughed blood and fainted during the Ikedaya Affair, but some sources say that he contracted the disease after that. While many of the Shinsengumi fans believe that Yoshida Toshimaru was killed by Okita during the Ikedaya Affair (based on Shimosawa Kan and Shiba Ryoutarou’s fiction), it is in fact historically inaccurate.
Based on Shiba Ryoutarou’s fiction, many also believe that Okita and Hijikata were like brothers. In history, Yamanami Keisuke was the vice-commander Okita shared a brotherly relationship with. Yamanami’s seppuku (with Okita as his second) in 1865 was an extremely painful incident in Okita’s short life. There is no record showing that Hijikata and Okita were close; it is debatable whether Okita even got along with Hijikata.
In 1865, Okita became the captain of the first unit of the Shinsengumi and also served as a kenjutsu instructor; later that year, he was appointed by Kondo Isami to be the fifth master of the Tennen Rishin-ryu after him.
Although highly unlikely, it was rumored that he wielded a famous katana called Kikuichi-monji. However, he surely owned a set of Kaga Kiyomitsu (a katana and a wakizashi) and his so-called “Kikuichimonji Norimune” was likely a Yamasiro Kunikiyo instead.
During the Boshin War, after the Battle of Toba-Fushimi in 1868, Okita went into Matsumoto Ryoujun’s hospital in Edo. He then moved to a guesthouse with Okita Rintarou, Okita Mitsu, and their children. When the shogunate forces (including the Shinsengumi and the Shinchougumi) retreated to the Tohoku region, Okita remained in Edo alone. He died on July 19 (lunar calendar May 30th), 1868. Later that day, he was buried at his family temple in Edo (present Tokyo), under his birth name (with Okita Souji listed in the death records.) Today, Okita’s grave is not open to the public.
The information that Okita died when he was 25 is based on the theory that he was born in 1844 and therefore was 25 by East Asian age reckoning when he died in 1868 (or on a lesser-known theory that he was born in Summer, before July 19, 1842 and therefore was 25 by Western standards when he died in July 19, 1868.)
Okita was known as a man who smiled and laughed well (not very talkative, however.)
It is historically accurate that Okita loved children. During his time in Kyoto, he was often seen playing with children and was a baby-sitter to Yagi’s sons in Mibu.
He was not particularly fond of liquor but it is fictional that he loved sweets.
Okita was a bit of a clean freak.
Aside from being treated by Matsumoto, Okita also took Kyorou Sanyaku (medicine for enervation and coughing) for his tuberculosis (not to be confused with Ishida Sanyaku for treating injures such as bruises and broken bones.)
Mori, Makiko. Okita Soji Feature. Tokyo: Shin Jinbutsu Oraisha, 1999. ISBN 4404028075
Oji, Kazuko. Walking with Okita Soji. Tokyo: Shin Jinbutsu Oraisha, 1989. ISBN 4404016212