Youshun is the Second-In-Command of the "second generation of the band of chivalrous thieves, the Condors of Sa Province" and Shourin's younger brother. His adoptive father is Hokuto, a former assassin of the Wolves of the Wind. Shourin and Youshun were placed in charge of taking care of Sa Shunki by Rou Ensei.

(Source: Saiunkoku Monogatari Wiki)