Hiryū no Hōfuku (飛龍の報復; Literally meaning "Retaliation of The Flying Dragon") or simply called the Hiryū is a secret international anti-crime organization founded by Ryūsuke Senju after he killed the assassin of her mother. The idea of the creation of this group came after he realized that there is a very dangerous threat from an "organization" in related to the assassin.