Shotokan

Shotokan is the colloquial term used to describe the fighting style used by characters such as Ryu, Ken Masters, Akuma, and Gouken.

Origin of the term
Capcom USA originally referred to the fighting style as "Shotokan", despite it bearing little resemblance to the discipline. Because of this, Ryu and other characters who use similar styles are still called "Shoto clones" or "shotos" by fans.

Storyline history
Akuma's fighting style was founded in Japan during the feudal age (according to Ryu's victory quote against Guile in the Japanese version of Capcom vs. SNK 2 and Zero's pre-battle dialogue in the Japanese version of SNK vs. Capcom: SVC Chaos ). The style used by Ryu, Ken, and their master Gouken is rooted in this very art, which is energized by the Satsui no Hado (殺意の波動, "Surge of Murderous Intent"), a evil energy that awakens within a warrior who has embraced the dark and violent aspects of their art, or else possesses an intense rage.

Gouken, who only wanted to embrace the peaceful and spiritual aspect of the art, developed a sublimated variation of the same martial art style by removing the Satsui no Hado from its techniques before passing down his version of the art to Ryu and Ken, so no one would have to suffer from it.