Ryuukou Yanagi 

Ryuukou Yanagi (柳 龍光, Yanagi Ryūkō) is a fictional character from anime and manga series of Baki. He is a Japanese convict who escapes from being enclosed in rocket-proof special glass. The smallest of the convicts physically, he is later being shown as the most deadly. He is the only convict whose crime is known, that he killed a dozen men in prison as a test bed for his new skill.