, was the captain of the first unit of the Shinsengumi

Shinsengumi

The were a special police force of the late shogunate period.-Historical background:After Japan opened up to the West following U.S. Commodore Matthew Perry's visits in 1853, its political situation gradually became more and more chaotic...

, a special police

Special police

Special Police does not have a consistent international meaning. In many cases it will describe a police force or a unit within a police force whose duties and responsibilities are significantly different from other forces in the same country or significantly different from other police in the same...

 force in Kyoto

Kyoto

is a city in the central part of the island of Honshū, Japan. It has a population close to 1.5 million. Formerly the imperial capital of Japan, it is now the capital of Kyoto Prefecture, as well as a major part of the Osaka-Kobe-Kyoto metropolitan area.-History:...

 during the late shogunate period. He was one of the best swordsmen of the Shinsengumi, along with Saito Hajime

Saito Hajime

was a Japanese samurai of the late Edo period, who most famously served as the captain of the third unit of the Shinsengumi. He was one of the few core members who survived the numerous wars of the Bakumatsu period.-Early years:...

 and Nagakura Shinpachi

Nagakura Shinpachi

was the captain of the 2nd troop of the Shinsengumi.-Background:Nagakura Shinpachi Noriyuki, known as Eikichi or Eiji during his childhood, was born in the Matsumae clan's "kami-yashiki" in Edo on the 11th day of the fourth month of Tenpō 10 His father, Nagakura Kanji, was a retainer of the...

.
He was born in 1842 or 1844 from a samurai

Samurai

is the term for the military nobility of pre-industrial Japan. According to translator William Scott Wilson: "In Chinese, the character 侍 was originally a verb meaning to wait upon or accompany a person in the upper ranks of society, and this is also true of the original term in Japanese, saburau...

 family in the Shirakawa Domain

Shirakawa Domain

The ' was a Japanese domain of the Edo period, located in Mutsu Province. Its most famous ruler was Matsudaira Sadanobu, the architect of the Kansei Reforms.Shirakawa was also the scene of one of the battles of the Boshin War.-List of lords:...

's Edo

Edo

, also romanized as Yedo or Yeddo, is the former name of the Japanese capital Tokyo, and was the seat of power for the Tokugawa shogunate which ruled Japan from 1603 to 1868...

 mansion. His great-grandfather was Okita Kan'emon (d. 1819) and his grandfather was Okita Sanshiro (d. 1833.) 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 Rintarō

Okita Rintaro

was a Japanese samurai of the late Edo period who was a commander of the Shinchōgumi .-Biography:...

 (1826–1883), his oldest sister Okita Mitsu became an adopted daughter of Kondo Shusuke in name.