Sôga, also called Souga, stands as a central figure in the story of Raoh’s rise to power. He is the older brother of Reina and a childhood companion of Raoh from the Land of Asura. After leaving their homeland, both siblings became part of Raoh’s campaign, with Sôga taking on the vital position of military strategist within the King of Fist's Army. His martial prowess is marked by his mastery of the Sūzan Senpū Kyaku, the Mount Song Whirlwind Kick, which granted him the epithet “Souga the Swift Foot” or “Souga the Fleet-foot.”

A pivotal moment in his past occurred at the prison of Cassandra, where Sôga sacrificed his right leg to a trap to secure the escape of Raoh and Reina. This injury led to the implantation of a mechanical prosthetic, which later enhanced the force of his kicking techniques.

Sôga demonstrated unwavering loyalty to Raoh’s ambition, frequently expressed through ruthless pragmatism. Following an encounter with an individual named Ryuga, he is said to have forsaken his humanity to advance the cause of conquest. His strategic brilliance was revealed in extreme actions, such as orchestrating a feigned assassination attempt on Raoh. This scheme aimed to instill discipline in complacent soldiers, and Sôga ultimately perished by his leader’s hand as part of the deception. The intricacies of the plot were later disclosed to his sister, Reina, in a letter that detailed the collusion between Raoh and the assassin.

His physical state remained a constant struggle, as he suffered from a terminal illness. During a confrontation with a warrior called Gaiya, Sôga received a fatal injury that left him with only two months to live. Despite his steadfast devotion to Raoh’s path of conquest, his final wish was to witness a reconciliation and unification between Raoh and his Hokuto brothers, Toki and Kenshiro, in pursuit of true supremacy.