Raoh is the eldest of the four adopted
children trained by Ryuken, the previous Hokuto Shinken master. The
manga gives two different origins through the course of the story.
In his first origin, Raoh and his biological younger brother Toki,
were adopted by Ryuken after their real parents died. The second
(and real) origin shows that a young Raoh and Toki, along with an
infant Kenshiro, were actually refugees from the Kingdom of Shura
who were sent to Japan to be trained in the art of Hokuto Shinken
by Ryuken after their homeland was torn apart by a civil war.
Raoh trained under Ryuken along with Toki and Kenshiro, as well as
another student named Jagi. In spite of his ambitions to become the
greatest martial artist in the world, Raoh lost the rights to the
Hokuto Shinken succession to Kenshiro. Refusing to give up the
style, Raoh killed his sifu Ryuken in combat and leaves to become
the savior of the world.