Raiden

The leader of the Sanmenken and master of Daiou Jouryuu taijutsu, the oldest form of Chinese Kenpo in history (fictional). He has a tattoo of Daioujou (大往生) on his forehead. Uses knived shoes and fights with three monkeys later. He fights J in the Daiyon Kyousatsu 1st Assault Shakumyaku Ioukan (灼脈硫黄関, Scorching Sulfur Vein Ring). At first his taijutsu overwhelms J, but J ends the match in a draw with one of his Mach Punches. After this he enrolls in Otokojuku with Date and the other Sanmenken. He is very serious and loyal but has occasioanly shown a comical side. He is always training in all forms of Kenpo, and therefore can usually recognize and explain all enemy's techniques or identities.

He is thought to be killed in the fight with Ryoukou, the boss of the Excellent Ryouzanpaku 16, but returned alive later (source : Wikipedia)