Shirokiba Senju

"Who is this Sigma Uchiha!? Next Ryūkage this next Ryūkage that! When I see him, I'll challenge him on the spot."

- Shirokiba about Sigma

 (しろきば, Nara Shirokiba) is the head ninja of Ryūgakure, as well as a member of both Inuzuka and Nara clans. While being a test subject of Orochimaru's, he was saved at a young age by Omega Uchiha. He know claims to be the "rival" of Sigma Uchiha.