Serizawa Kamo (芹沢 鴨, Serizawa Kamo) was a samurai, turned rōnin, of the Bakumatsu. Together with Kondō Isami, he led the Shinsen gumi, the most powerful of the samurai groups that, under the orders of the Tokugawa shogun, was to maintain order in Kyoto during the Bakumatsu at the end of the Edo era (1860-1868).
The Serizawa family is a goshi, a high ranking country samurai from Serizawa village near Mito. Kamo's childhood name is Genta, and he has two older brothers and a sister. He studied the ideas of Mitogaku and kenjutsu at Mito estate.
Kamo was a priest of a Shinto temple in Kimura family, whose daughter he married, taking the name of Kimura Keiji. In 1860, he joined an extremist anti-foreign group, the Tengu-to, responsible for the assassination of the tairo Ii Naosuke. He made a reputation for himself and climbed up the hierarchy. At the beginning of 1861, he had three members who had broken the rules beheaded.
Very quickly, the Bakufu hunted down and imprisoned the members of the Tengu-to for their participation in the assassination of Ii. Serizawa was released at the end of 1862, and from Kimura Keiji he became Serizawa Kamo, and joined the Roshi gumi of Kiyokawa Hachiro.
On September 18, 1863, after a celebration, Serizawa, drunk, returned to Mibu with Hirayama Goro and Hirama Juusuke. He was executed in his bed with his mistress. Hirayama is killed and Hirama runs away. The executed men were buried in an official ceremony and bandits were accused of the crime.
Those who were chosen to take part in the plot were undoubtedly trusted men of Kondo and Hijikata. Hijikata and Okita took care of Serizawa, Yamanami, Inoue and Harada took care of Hirayama and the surveillance. It is highly unlikely that Kondo himself was involved.
There were a number of theories about the motive for the assassination.
His full name was Serizawa Kamo Taira no Mitsumoto. "Serizawa" was his family name, "Kamo" was his first name, "Taira" was the name of his clan (his ancestors), "Mitsumoto" was his formal name (the equivalent of a middle name).