Street Fighter Alpha: The Animation, released in Japan as and also known as Street Fighter Alpha: The Movie on the home video packaging, is a 1999 original video animation (OVA) film based on the Street Fighter Alpha fighting games. It was directed by Shigeyasu Yamauchi, with character designs by Yoshihiko Umakoshi. An English dubbed version was released in 2000 by Manga Entertainment.
The movie begins with the martial artist Ryu contemplating the death of his master, Gouken. As he's thinking about this, a shootout is taking place nearby. Chun-Li, an agent of Interpol, is engaged in combat with several thugs from the Shadowlaw organization. The situation takes a turn for the worse when a small boy is taken hostage by one of the thugs. It is at that point that Ryu jumps in, rescues the boy, and uses his special techniques on the criminals. Both Chun-Li and Sakura, an energetic high school girl, are in awe of his skill.
Ryu returns to Gouken's grave to pay his respects, when he suddenly has a strange vision, in which Rose tells him that he must grow stronger in order to control the darkness. This vision is interrupted, however, when Ryu encounters his old friend and training partner, Ken. As they place flowers on the tomb, and Ken leaves to get some water for them, Ryu is suddenly overcome by the power of the Satsui no Hadou, with images of the warrior Akuma flash through his mind. Ken rushes back up to Ryu when he witnesses a large release of energy from his general area. He sees Ryu lying on the ground, and a young boy standing near him.
The boy reveals himself to be Shun, Ryu's little brother, though both Ryu and Ken have their doubts. Regardless, they let him train and live with them for a while. One night, though, the Dark Hadou swells within him again. After Ken calms him down, Ryu tells him to kill him if the power ever completely overtakes him. Later, a new Street Fighter tournament is announced. Ken and Shun are both prepared to enter, but Ryu decides it best that he stay out, for fear of the Satsui no Hadou within him.
As they seek out the location of the tournament, Ryu and Shun are attacked by a few rowdy street thugs. Shun displays his skill by beating the thugs senseless, but then he begins to take it overboard, almost strangling one to death, until Ryu tells him to stop. They're located by Chun-Li, who requests Ryu's help in tracking down Shadowlaw. As they enter the tournament building, they witness a rather bloody battle between Dan and Vega.
Meanwhile, Ken runs into Sakura, who's being attacked by drunks in a bar. Ken promptly takes them out, and when Sakura asks if he knows Ryu, he takes her to the place where he left the brothers, only to find that they aren't there. They proceed into the tournament building, but Ken discovers that it's too late to sign up. Instead, he decides to go witness the fight already occurring. At this point, Shun is fighting the burly Russian wrestler, Zangief. Shun holds his own for a while, displaying the same raw brutality that he did in the previous fight. However, when Ryu starts to see that Shun is in trouble, he intervenes in the fight. At that point, the Satsui No Hadou begins to corrupt his mind once again. Ryu fires off a Hadoken which just barely misses Zangief, but causes the building to collapse. Zangief falls through the crumbling floor. Dr. Sadler, the sponsor of the tournament, is impressed by Ryu's power. As Ryu asks Shun where he learned the power of the Satsui no Hadou, they are approached by a gigantic cyborg of Dr. Sadler's, who attacks Ryu. Chun-Li jumps into the fight, but neither of them have much success against the beast, and just as it's about to blast Ryu into an unconscious state, Shun gets in the way and takes the shot for him. The Satsui no Hadou overtakes Ryu again, and he incinerates the cyborg with a Shinku Hadoken. Shun is then carried away by Shadowlaw agents in a helicopter. Ken carries Sakura, who now has a broken leg, to the hospital.
At this point, Ryu has completely lost the will to fight, even allowing a few street thugs, who he typically would have taken care of in a matter of seconds, to beat him to a pulp. Ken visits Sakura in the hospital, telling her only to continue fighting if she's really serious about it, because it's also a road to pain. Ryu has another vision with Rose, who tells him to save Shun from both Dr. Sadler and from himself. Ryu eventually decides that he's going to rescue Shun, but first, he has to see somebody.
Ryu and Chun-Li venture out to a wheat field filled with what look like wooden tombs. Akuma's voice can be heard, and he recognizes Ryu as a student of Gouken. It is apparent that Ryu has come here to test his self-control over the Satsui no Hadou. He then asks Akuma if he has a son, referring to Shun. Akuma wanders off, telling him that where he goes, he goes alone.
Ryu is later confronted by Ken, who wants to remind him that he can be strong without resorting to murder. They engage each other in a short but brutal fight which ends in a perfect draw. As they both lie on the ground, breathing heavily, Ryu once again asks Ken to kill him if the Satsui no Hadou completely consumes him. Ken reluctantly agrees through a silent nod.
The various fighters duke it out in Sadler's arena, while Ryu, Ken, and Chun-Li investigate. Birdie, being the first winner, is led to a room by Sadler's men, gassed and imprisoned. Later, he's freed by Ken and Chun-Li. Ryu wanders off and finds a garden filled with children in white robes. Ryu sees a boy that looks like Shun but has freckles and blue eyes, and as the boy stares soullessly at Ryu he suddenly crumbles to the ground and starts convulsing, apologizing to Sadler.
As Ken and Chun-Li carry away Birdie, they are attacked by what seems to be the same cyborg that Ryu destroyed during the earlier tournament. It makes quick work of Birdie, and Ken tells Chun-Li to leave with him while he stays behind and fights the cyborg. It fires a blast of energy at Ken, then captures Birdie and tries to carry him off. Birdie wakes up and tries to sneak attack the cyborg, but he's quickly defeated once again. Chun-Li tries to take him down too, but she's also defeated. Ken returns, and the cyborg takes a lot out of him, but Ken attempts to stay up and continue the fight. Ryu arrives at the scene, only to realize that the cyborg they've been fighting is actually Shun, who has been luring him into a trap. He tells Ryu that if he doesn't use the Satsui no Hadou, Ken will die. Ryu attempts to take him down without using any lethal techniques, but as he does, the data from the fight is pumped into Sadler's body, making him more powerful. None of his attacks are particularly effective, and Shun keeps taunting him. He becomes enraged as Shun proceeds to use a Shinku Hadoken on Ken who has collapsed due to his injuries. In a desperate final assault, Ken unleases his powerful Shoryuken on the Cyborg dislocating its jaw before collapsing once more, this time unable to continue fighting. In Ryu's desperation, he once again gives in to the Satsui no Hadou, firing a Hadoken right through the cyborg's abdomen, blasting Shun out of its body.
Sadler then emerges from his lab, with a new, pumped up body, and attacks Ryu with a vicious barrage of punches, kicks and headbutts. As Ryu powers up a Messatsu Hadoken, his friends, as well as Shun, ask him not to use the Satsui no Hadou but he shoots one anyway. Sadler fires a Hadoken which overwhelms Ryu. Amidst Sadler's attack Ryu returns to a normal state yet stronger than ever, and fires a Shinku Hadoken that disintegrates Sadler.
Shun tells Ryu that the reason he lied and worked for Sadler was so he could get money for him and his mother to survive. Ryu tells Shun that he'll never use the Satsui no Hadou again. After that, Shun dies, and for a moment, Ryu almost gets emotional. He puts Shun's dead body down and is driven with a greater than ever desire to fight.
The movie ends with the fighters returning to their normal lives, and a sparring match between Ryu and Akuma.