First appears in volume 2. Yellow Radio being the Yellow King makes him a very powerful and commanding person. He is also very cruel and manipulative person as he was the one who stole the chrome disaster armor and essentially created the fifth one in order to exploit the rules that allows him to kill the Red King. He along with the Kings of Pure Color attained level nine and decided to create a treaty that seperates their territories and disallowed fighting amongst each other to obtain level ten. (Source: Accel World Wiki)