Hiryu Niwa is a Japanese grappler who specializes in jiu-jitsu, a discipline where he holds the rank of black belt under Guilherme Mendes. Hiryu Niwa first gained notoriety in this discipline while competing on the International Brazilian Jiu-Jitsu Federation (IBJJF) circuit, representing the Art Of Jiu-Jitsu academy, a team led by the Mendes Brothers (Guilherme & Rafael).