Seiwa Genji
The Kira clan(吉良氏 - kira-shi) was a Japanese clan, descended from Emperor Seiwa (850–880), and was a cadet branch of the Ashikaga family from the Minamoto clan (Seiwa Genji). Ashikaga Mitsuuji, grandson of Ashikaga Yoshiuji (1189–1254) was the first to take the name of Kira.