Originally appearing in Super Street Fighter II Turbo as a secret character and hidden boss, he is Gouken's younger brother and Ryu's adoptive uncle. Akuma is voiced by Tomomichi Nishimura in all of Capcom's 2D Games, but in Street Fighter IV and Marvel VS. Capcom 3, he is voiced by Taketora. His Mortal Kombat rival is Scorpion.
Akuma and his brother Gouken were students of Goutetsu. Goutetsu taught a nameless life-threatening martial art, which incorporates elements of Karate, Judo, and Kempo. He also taught the Shun Goku Satsu (literally Instant Hell Murder), a death technique which, although incredibly powerful, puts the user in considerable danger.
As the brothers progressed under Goutetsu's tutelage, a dispute arose on the true nature of their fighting style and the path to master it. Gouken, unable to accept the violent nature and the Satsui no hadou of his fighting style, left Goutetsu to begin his own dojo, however Goutetsu did not stop his student Gouken from leaving and even allowed him build his own dojo. Akuma continued Goutetsu's teachings and vowed to use their fighting style as it was intended.
In order to learn Shun Goku Satsu, Akuma embraced the principle of Satsui no Hadō or (The Surge of the Intent to Kill/Killing Intent). Through Satsui no Hadō, Akuma was forced to give up any compassion he held towards other human beings. In addition, Akuma realized his limits as a martial artist could be expanded, and left Goutetsu's guidance of enlightenment to train alone to gain more power, but after embracing the Satsui no Hadou to his fullest extent, he develop a lust to fight to the death, unlike Goutetsu who was able to use the Satsui no Hadou without given in to the dark side effects of it and not give in to his fullest extent, after he came back from his island, he went back to Goutetsu, he fought and killed him with Shun Goku Satsu. Akuma, believing that he was the true master of the Art, took the prayer beads of his dead master and placed it on his neck, when Gouken went to visit his Master to see how he was doing, he only found his body lifeless and saw his brother was not looking human at all. Gouken, who was in shocked to see that his younger brother took the life of their master, yelled at Akuma for killing Goutetsu. Akuma however, said nothing and just left Gouken and Goutetsu and went into the Woods.
Many years later, Akuma fought Gouken, while Ryu and Ken watch the whole battle at a young age, Akuma told Gouken that he was not enough to face him without giving in the Killing intent, Gouken had told him that the art is much more then just death and destruction and even saying that he has dishonored our master's name, Akuma had told his brother that Goutetsu did not truly understand the art and was a fool for not using the Satsui no Hadou to his fullest intent, while the brothers fought well, Gouken won the battle. Akuma had told his brother to kill him, but Gouken had no intention of murdering his own kin, Akuma then told Gouken that he is weak for sparing a life of a strong opponent and said that he will return. A couple years later, Akuma came back to Gouken's dojo and fought him in battle, Akuma had used Shun Goku Satsu on his brother and believed to had killed him, not knowing that Gouken had somehow lived through the attack by emptying his soul and was only in a coma. Ken saw the flash of the attack while running to the dojo, only to find Gouken on the floor, Ken knew that Akuma did this and went after him, as he found Akuma in the woods, he fought him, only to be defeated by Akuma, after defeating Ken, Akuma had went into the woods without a trace.
Akuma begins to search the globe looking for worthy fighters to challenge. Secluding himself in the shadows, he watches small tournaments and street fights, desperately seeking someone who might be able to match his strength. He is eventually challenged by a man named Gen. Gen fights a vicious battle, even surviving the Shun Goku Satsu by emptying his soul in time. Just as Akuma begins to wonder whether this man is the worthy opponent he's searching for, he begins to sense not all is as it seems when Gen's mouth begins to bleed, Akuma's suspicions are confirmed: his opponent is sick, and the fight is not fair. After being knocked to the ground, Gen tells Akuma to kill him. Not wanting to carry the fight on any longer, Akuma leaves, infuriating Gen. After the fight, Akuma becomes obsessed with Ryu, hoping to awaken the Satsui no Hadou within his prey.
Ryu eventually finds Akuma's island (known as Onigami Isle or the Gokuentou) and challenges him. The intense battle that ended in Ryu gaining the upper hand; in truth Akuma was only testing him. Akuma regains composure and tells Ryu to find him again when he has embraced the Satsui no Hadō, Akuma strikes the ground with a powerful blow and disappears. The island falls apart around Ryu, who is left in the ocean to contemplate Akuma's words. Leaving his destroyed abode, Akuma thinks about all the fighters he has encountered and wonders with excitement if one day he will fight someone strong enough to kill him in battle. This thought drives him on; finding a desolate cavern (also known as Kiga Cave) he begins to train anew and await the day when he will fight Ryu again. At some point, he defeats a Muay Thai fighter who was about to challenge the champion, Adon. Adon sees this as a challenge and sets out to find Akuma, to fight him and prove that he is stronger.
In his ending, he comes to the realization that worthy opponents have challenged him during his journey. He decides that he could stay on Earth to perfect his killing power, knowing that there are opponents that Akuma can consider worthy. While thinking about the opponents he challenged, there were visions of Gen, M. Bison and Ryu on the moon. He then makes a comment, saying he will be the next to die.
Two years later, Akuma begins to search once more for worthy fighters whilst awaiting Ryu to embrace the Satsui no Hadō, he was found and was fought by Adon, who wanted prove that his fighting stye was the greatest but was defeated easily by Akuma, however Akuma did not kill him and just left him. Akuma encounters Gen once more and fights a second battle (the results of the fight are unknown). However, unbeknownst to Akuma, Ryu rejects the Satsui no Hadō while battling the Shadaloo leader, M. Bison, declaring that a true warrior does not rely on violent intent.
Akuma does not officially enter the second World Warrior tournament, although he fought and does perform the Shun Goku Satsu on Bison. Akuma stated that Bison was pathetic for letting dark energy control him rather than him controlling such power (despite the fact that Bison is in control of is own power). Bison's body is eventually regenerated by Shadaloo scientists.
During the events of Seth's tournament, he continues his training, and senses the Satsui no Hadou reemerging within Ryu. Immediately, he sets off to find Ryu and help him realize this power so he can try to kill him in battle. Like the other tournaments, Akuma does not officially enter, but stays in the shadows. Eventually, he finds an unconscious Ryu in the care of his brother Gouken. Akuma noticed that his brother has perfected the Mu No Ken (Empty Fist). The two brothers then proceed to fight; Ryu, being the prize. Both survived their fight and Ryu was saved by Gouken. So Akuma continued his training and still searches for a worthy opponent to match his own.
As with the second World Warrior tournament, Akuma did not enter the third World Warrior tournament, but once more lurked in the shadows. He even successfully pulled off a Shun Goku Satsu on the tournament sponsor Gill, although he left without realizing that Gill had resurrected himself. Over this time-span, Akuma had trained relentlessly until finally harnessing his power and learning several new techniques, some that were meant to create tidal waves, some described as strong enough to split Uluru (Ayers Rock) in half, and one that could kill an opponent with a single strike. Akuma's self-taught technique is called the Kongō Kokuretsu Zan, in which Akuma channels all his power into one hand and smashes it into the ground, creating a vortex of energy upward around him. It is supposedly this technique that was used to destroy his original training ground.
Akuma continued to develop his now-incredible fighting skill, and even fought with Oro in a simple, inconclusive battle, with each other sensing the other's massive chi and testing their powers. Though mutually impressed by each others power, both men expressed some contempt for the other on a personal basis. Akuma has now demonstrated the ability to remain underwater under massive pressure for extended periods of time, and has even managed to destroy a naval submarine with a technique that he has dubbed Tenshō Kaireki Jin.