One of the Hachiyō, he is the Seiryū of Heaven and is also a samurai in the service of the Imperial court.

Being a descendant of a proud samurai line Yorihisa has been trained with a sword for as long as he can remember, because of this he is acknowledged to be a fearsome opponent.
Yorihisa was raised by his older brother Sanehisa; until his Sanehisa’s untimely death during a mission to protect a young lord; Yorihisa blames himself dearly for his brother's death due to ultimately being saved by Sanehisa in exchange of his own life.
Because of this guilt, he takes protecting everyone within the group very seriously, even to the extent of being willing to pass off his own life for them, this is especially true with Akane for whom he holds a strong sense of duty towards protecting.