The Kira clan was a Japanese clan, descended from Emperor Seiwa

Emperor Seiwa

was the 56th emperor of Japan, according to the traditional order of succession.Seiwa's reign spanned the years from 858 through 876.-Traditional narrative:...

 (850-880), and was a cadet branch of the Ashikaga family from the Minamoto clan

Minamoto clan

was one of the surnames bestowed by the Emperors of Japan upon members of the imperial family who were demoted into the ranks of the nobility. The practice was most prevalent during the Heian Period , although its last occurrence was during the Sengoku Era. The Taira were another such offshoot of...

 (Seiwa Genji).

Ashikaga Mitsuuji, grandson of Ashikaga Yoshiuji (1189-1254) was the first to take the name of Kira.

Kira Mitsusada sided first with his relative Ashikaga Takauji

Ashikaga Takauji

was the founder and first shogun of the Ashikaga shogunate. His rule began in 1338, beginning the Muromachi period of Japan, and ended with his death in 1358...

 (1305-1358), the first Ashikaga Shogun

Shogun

A was one of the hereditary military dictators of Japan from 1192 to 1867. In this period, the shoguns, or their shikken regents , were the de facto rulers of Japan though they were nominally appointed by the emperor...

, then passed over to the Southern Dynasty. He was defeated by Hatakeyama Kunikiyo (1360) and submitted to the Ashikaga shoguns.

In fact, the Kira, from Mikawa province, were a minor branch of the Minamoto clan

Minamoto clan

was one of the surnames bestowed by the Emperors of Japan upon members of the imperial family who were demoted into the ranks of the nobility. The practice was most prevalent during the Heian Period , although its last occurrence was during the Sengoku Era. The Taira were another such offshoot of...

, as they never had the rank of Shugo

Shugo

was a title, commonly translated as "Governor," given to certain officials in feudal Japan. They were each appointed by the shogun to oversee one or more of the provinces of Japan...

(governor) of any province during the Kamakura period

Kamakura period

The is a period of Japanese history that marks the governance by the Kamakura Shogunate, officially established in 1192 in Kamakura by the first shogun Minamoto no Yoritomo....

 until the Sengoku period

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

, they never possessed important domains and never represented a real power, in comparison with other great Seiwa Genji

Seiwa Genji

The ' were the most successful and powerful of the many branch families of the Japanese Minamoto clan. Many of the most famous Minamoto warriors, including Minamoto Yoshiie, also known as "Hachimantaro", or God of War, and Minamoto no Yoritomo, the founder of the Kamakura shogunate, were descended...

 families.

During the Tokugawa period, they were among the koke

Koke

A was a noble ranking below a daimyo in Japan during the Edo period. Their lands were assessed at less than ten thousand koku, making them ineligible for the rank of daimyo.Unlike hatamoto, whose duties were military, the kōke had certain privileged missions...

, a ranking below Daimyo

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

. The Kira are famous for Kira Yoshinaka

Kira Yoshinaka

was a kōke . His court title was Kōzuke no suke. He is famous as the adversary of Asano Naganori in the events of the Forty-seven Ronin...

 and the Forty-seven Ronin

Forty-seven Ronin

The revenge of the , also known as the Forty-seven Samurai, the Akō vendetta, or the took place in Japan at the start of the 18th century...

vendetta.