On Jul 16 1988 an atom bomb vapourizes Tokyo. It is now 2019 in Neo-Tokyo, 31 years after WW3. In a grungy part of town, a man goes to a bar, the bartender is selling drugs to a customer and the TV recaps the days news, there is unrest due to unemployment and the economy. An angry young man enters and gathers some friends from a back room, they will be going after the Clowns on Route 5. Outside a younger teen is admiring a bright red motorbike with special technical features. The gang leader in the red suit mocks the younger calling him Tetsuo.
The motorcycle gangs chase through the skyscraper district where Clowns are knocked off their bikes and bystanders cars are damaged and bombed. Tetsuo wipes out and is left alone.The police arrive and the two gangs split.
A wounded man leads a short green skinned person throught the streets, he pulls a gun and kills a chasing dog. The man is dripping blood and is cornered by the police close to a group of rioting protesters, he is shot and the green-skinned little person is terrified. He screams and a building starts to collapse and the crowd scrambles for safety. A moustachioed man and his companion, a young woman named Kei, split up.
Motorcycle chase continues, Tetsuo is chasing a Clown on his own. At the crowd, police use water cannons and tear gas. Tetsuo closes in on his prey, a rider with a red cross logo. The red-cross rider wipes out and Tetsuo viciously hits the downed man in the head. Tetsuro looks up and is about to run into the green-skinned little man. A crash and explosion. The leader and his gang arrive to find Tetsuo semi-conscious on the street. The red-suited leader calls out to the little green person walking away into the dark. Another green skinned little person in a hoverchair comes down and talks to the other in a child's voice to return, there is "no escape". A helicopter with an armed paramilitary group lands and forces the motorcycle gang to the ground and a tall man with a jarhead haircut comes out of the helicopter. The helicopter flies away with the tall man and the two green skinned children. The red-suit leader is called Kaneda and the gang is taken into custody. A the police station a cop mentions 8 clowns are in hospital but releases the motorcyclists. Kaneda notices the young woman Kei from the riot in another group of prisoners and manages to have her released with him. Unknown to each other, she teases him for his attempt at flirting and she slips away.
Tetsuro is placed in a full body scanner. The jarhead Colonel and a politician talk in an office, discussing a "mole" on the Executive Council. Summoned by telephone, the Colonel meets a scientist, Doctor Onishi, in a lab who shows a 3D display and mentions that Tetsuo may hold the key to solving "Akira's" growth pattern. The two talk of the dangers of uncontrolled god-like power and "level 7" pills.
The gang members are in school, a vandalized wreck. Girlfriends join them to discuss the previous night, they are suprised the police and army are working together. A timid young woman is concerned for Tetsuo. A nurse raises an alarm, Tetsuo has escaped. He meets the timid girl, Kaori, and they plan to run far away.
Tetsuo takes Kaneda's red motorbike. Kaneda and pals notice him leaving with Kaori and start a search. The bike stalls and a three Clowns confront Tetsuo and Kaori. They tear her shirt off and threaten to torch the red bike when suddenly Kaneda and friends arrive. Kaneda kicks a Clown off his bike and they all watch as Tetsuo takes out his frustrations on the Clown. Tetsuo is angry at having to be rescued. He begins to hallucinate, hears the word "Akira" and suffers severe head pain. The scientists pinpoint his location on a scanning device and the watchers send in a CRC team, who arrive by armoured vehicle and choppers to take Tetsuo away and leave Kaneda and his gang. Later the gang discuss what happened.
Nearby an explosion rocks a building and police shoot and kill fleeing armed men. The moustached man and Kei are there too. Kaneda notices Kei and follows her. The police flashlights bracket Kei as she attempts to escape. Kaneda gets in the way and a cop is shot and killed.
Tetsuo recalls his days as a young boy. His memories turn into a nightmarish hallucination. The Colonel approaches a green-skinned aged-looking young girl in a large crib, as as the Doctor scans printouts. The girl, Kiyoko, has a "25" tattoo on her palm and makes an ominous prediction.
The Colonel and scientists fly to a place with an oval track-like shape, donning parkas. They enter a frigid facility and begin turning on the equipment. A massive door slowly opens the Colonel enters a cavernous chamber. There is a small red light and sign "Akira 28".
Kaneda and Kei make their way to the hideout of the Resistance, Kei calls the leader, the moustachioed man, Ryu. They discuss the earlier failed effort to kidnap #26. The group reviews their next assignment: to gain access to a government facility to find out what they can about a new test subject named Tetsuo Shima. After being discovered eavesdropping, Kaneda explains to the suspicious group that he and Tetsuo are friends, and that he can help.
Ryu meets a short old man, Nezu. As they observe the fires and the protests in the street, Nezu speaks of Akira as a symbol of hope and instrument of change.
Appearing before the Supreme Executive Council, the Colonel is angered when the Council members scoff at his requests for further funding for the project, and question his sense of duty as a soldier. The Resistance leader Nezu is a Council member smiling at the Colonel's distress. Frustrated by the Council's harangue, the Colonel abruptly leaves the meeting.
In a hospital room at the government facility that night, Tetsuo has fantastic hallucinations of a toy rabbit, teddy bear and milk. Unsure of what is happening Tetsuo steps on a glass and cuts his foot which startles the green skinned children, who are apparently behind the hallucinations and frightened at the sight of blood. Tetsuo then breaks out of his room and uses telekinetic powers, killing soldiers and wreaking destruction in a painful rage.
Meanwhile, the Resistance group, having made it into the facility disguised as electrical workers, are spotted sneaking in the sewers and a chase ensues. During the violent shootout, Kaneda manages to takeover a "flying platform" -- a small aerial vehicle flown by soldiers -- and takes Kei as they flee the scene. Kiyoko possesses Kei and leads Kaneda to the government nursery, where Tetsuo has already arrived. Once again Tetsuo is upset that Kaneda has come to rescue him. He has learned about Akira and is eager to find out what it is, hoping to make his headaches stop. The three other psionic kids have weaker powers than Tetsuo. Tetsuo escapes, learning to fly, and heads for Akira's location beneath the city's Olympic Stadium, currently under construction.
Tetsuo first arrives at the bar in the beginning of the film, still dressed in his tattered hospital gown, and quietly demands "capsules" from the bartender, the only person in the bar. The scene then cuts to two fellow gang members, Yamagata and Kai, who discover the place to be trashed and see the bartender's dead body. They see Tetsuo sitting and giggling on top of a pile of rubble and furniture, and are perplexed and disgusted at what is happening, doubting that the person before them is really Tetsuo. Tetsuo speaks in a cryptic manner, angering Yamagata and frightening Kai. He then knocks Yamagata back a few feet before standing on top of the rubble and making an evil smile.
Kei and Kaneda are locked in a holding cell. Kiyoko speaks through Kei once again, warning of Tetsuo's immense power. The cell door becomes unlocked and the two escape. A government representative comes to arrest the Colonel, but his men support him and instead the Colonel initiates a coup d'etat. He mobilizes his men to the stadium. Upon hearing this at his home, the mole Nezu murders his staff. When Ryu arrives to inform him of the mission's failure, Nezu shoots him and leaves with a briefcase full of money. In an alley, Nezu later dies of a heart attack. Ryu, having followed Nezu, also dies from his wounds.
Kai manages to find Kaneda and Kei at an urban water-filled ditch and explains that he and Yamagata found Tetsuo, who acted strangely and somehow killed Yamagata. The blue-greened boy named Takashi then appears in the water and beckons Kei over, where they walk on the water before dissapearing. The voice of Kiyoko speaks to them and speaks of Tetsuo's sadistic misuse of his powers, and that they are trying to stop him. Kaneda yells at the voice and says that he is Tetsuo's longtime friend, and that he should be responsible for finding a way to destroy Tetsuo
Tetsuo is now wreaking havoc across Neo-Tokyo on his way to the Olympic Stadium, destroying tanks and helicopters. Kei, again possessed by Kiyoko, attempts to fight him but is soon thrown aside. When Tetsuo tears Akira's entire cryonic chamber from underground and opens it, he finds nothing left of except dissected body parts housed in canisters. Making his way though wreckage of the scene, Kaneda, now armed with a laser cannon, confronts Tetsuo, and they begin to fight. In the middle of the skirmish, the Colonel activates an orbital weapon called SOL, and its beam severs Tetsuo's right arm in the process. An enraged Tetsuo flies into space and pulls SOL out of orbit, causing it to disintegrate in the atmosphere. That night, Tetsuo hides out at the Olympic Stadium, where Kaori finds him screaming in pain. He has fashioned a new, apparently mechanical arm, which seems to throb with a life of its own. The Colonel soon appears, asking Tetsuo to come back to the lab with him, but Tetsuo attacks him. When the Colonel shoots back, Tetsuo's arm transforms into a horrific blob that attempts to swallow the Colonel. Kaneda arrives and shoots the monstrous appendage, causing it to recede. Meanwhile, the three green kids have arrived at the stadium and seem to be communicating with the canisters that Tetsuo took from the cryonic chamber. As Tetsuo and Kaneda fight again, Tetsuo's body swells into a huge protoplasmic mutation. Tetsuo's gruesome form grabs and kills Kaori, and nearly kills Kaneda before he can escape. Akira suddenly appears, revealed to be a young boy without a physical body. His arrival triggers another explosion. Kiyoko touches the Colonel, instantly teleporting him to safety. The explosive energy sphere starts to absorb Tetsuo, who pleads for Kaneda's help. Kaneda, desperate to save his friend in need, follows Tetsuo into the energy sphere. In an effort to save Kaneda, the three green kids decide to enter as well, intending to use their combined powers to free him. They tell Tetsuo that Akira will be sending him "away" (to an undisclosed destination). Kaneda then seems to be ejected from the inside of Akira's onslaught, awakening outside the explosion. Neo-Tokyo is partially destroyed by the violently expanding sphere; streets are gutted and flooded by the event, and Doctor Onishi is killed when his laboratory collapses.
Kaneda survives, as do Kei, Kaisuke (one of Kaneda's gang), and the Colonel. The former three meet up at the ruins of the Olympic Stadium, wondering if Tetsuo is truly dead. They then ride their damaged bikes across a bridge into the ruined city to start a new beginning. Somewhere, a stylized "big bang" breaches the cosmic darkness and Tetsuo's voice says "I am Tetsuo." Is Tetsuo now a god-like entity residing in his own universe?