Ryoga Kamishiro (神代（かみしろ）凌牙（りょうが）, Kamishiro Ryōga), nicknamed Shark is a character in the spin-off manga Yu-Gi-Oh! D Team ZEXAL. This is an alternate incarnation of Reginald Kastle, a character from the Yu-Gi-Oh! ZEXAL anime. He is a delinquent who leads Team Shark.