Mugen (無限, Infinite) is an incredibly dangerous technique, granted to only the Master of Taijutsu, Robon Hyūga. The technique was deemed as S-Rank by the Konohagakure council for it's extremely dangerous nature and absolute threat. The technique unlocks the pinnacle of the human strength as well as stamina, and when using it, Robon has a high risk of fainting and a medium risk of fainting. The blood veins begin pumping at the very maximum rate in the arms, allowing his attacks to inflict and cause fatal damage to both the environment, foes, and if not careful, he himself. The fists glow a steamy azure blue color, emitting colors that range from light blue to dark purple when punching, causing shockwaves. It allows jutsu to be performed twice as fast, and more effectively than before, allowing his gentle fist and taijutsu techniques to do much more damage.