Ryu and Ken's master, Gouken
Holy shit.
Brother to Gouki/Akuma, sensei and mentor to Ryu and Ken Masters, Gouken finally makes his debut in Street Fighter 4.
There's not much on Gouken's background, but I'll give it a shot.
Gouken's Background
Nationality: Japanese
Date of Birth/Age: Unknown/Unknown, probably in his late sixties
Height: Unknown
Weight: Unknown
Hair: White
Eyes: Brown
Blood Type: Unknown
Allies/Friends: Retsu, some also say he's friendly with Gen
Enemies: Gouki
Family: Gouki, younger brother; had a daughter whom Ryu and Ken called 'Little Miss' (whereabouts unknown); Ryu, student/foster son
Fighting Style: Ansatsuken, trained by Goutetsu
While earlier Street Fighter games made references to Ryu and Ken's master, the character made his first illustrated appearance in Masaomi Kanzaki's manga adaptation of Street Fighter II, originally serialized in Family Computer Magazine in 1992. According to the comic, Gouken accepted Ryu and Ken as his pupils and taught them their fighting style in his solitary home located in the Japanese wilderness. However, one day M. Bison and his men stormed the dojo and killed Gouken, leaving Ryu and Ken with the duty to avenge their master's death.
While the comic itself was non-canonical in the video game Street Fighter continuity, Gouken's name and character design was adapted in the Street Fighter video game series with the introduction of Akuma in Super Street Fighter II Turbo.
According to Capcom's official account of Akuma's backstory for Super Street Fighter II Turbo, Akuma and Gouken were practitioner of an unnamed assassination style taught to them by their master Goutetsu. While Akuma embraced the killing aspect of the art to the point of succumbing to the "killing intent" (Satsui no Hadou) and killing Goutetsu, Gouken developed his own style, turning techniques such as the Hadouken and Shoryuken into pure defensive non-killing techniques. Gouken would go on to pass his knowledge to Ryu and Ken before being challenged by Akuma and supposedly killed in combat. Gouken makes his first appearance in the video games in the first Street Fighter Alpha game in Akuma's ending in the game alongside their fallen master.
Gouken appears in Street Fighter IV as a secret computer-controlled challenger. His presence in the game was hinted months before his official appearance in the game, with Street Fighter IV project manager Natsuki Shiozawa showing a silhouetted illustration in his blog, claiming that the character was "Sheng Long" (a hoax character once assumed to be Ryu's and Ken's sensei as a result of a localization error), as well as featuring the character in an animated teaser for the console versions of Street Fighter IV and in Akuma's ending in the game.
Gouken throws the Hadoken with one hand, and if used as an EX move, he throws a second one upward at a 45 degree angle. He possesses Akuma's Hyakki Shu somersault move, as well as a special move version of his Super Art from the Street Fighter III games, the Messatsu Gou-Rasen, apparently called the Gou-Rasen Senpu Kyaku. His Super Combo is the Kinjite Shoryūken or "Forbidden Dragon Punch", while his Ultra Combo is the Shin Shoryuken, one of Ryu's Super Arts from Street Fighter III. Gouken's Focus attack is a high kick similar to Ryu's Joudan Sokutou-Geri from the Street Fighter III games.