According to the backstory that was developed for "Super Street Fighter II Turbo" and the "Street Fighter Alpha" series, Gouken and Akuma learned a murderous martial art style from their master, . It included the special techniques the "Hadouken", the "Shoryuken" and the "Tatsumaki Senpukyaku", 20 years before the "Street Fighter" tournament. After Goutetsu was killed by Akuma, Gouken refined these special techniques, eliminating the "murderous energy" they possessed and developed them into a purely combative martial art. He would then teach this new style to two students, Ryu and Ken. Gouken also trained Dan at one time, but then expelled him after seeing that Dan was motivated by revenge.