2030. The world hovers on the brink of World War IV. Kaneda, leader of a band of teenaged delinquents, brings his gang to a restricted area--the section of Neo-Tokyo known as the "old city"--where, thirty-eight years before, the first of the bombs fell.
As a result Kaneda and his friend Tetsuo become entangled in a power struggle between a mysterious military and scientific organization led by a man known only as the Colonel and an underground resistance group bent on putting a stop to the Colonel's activities. Members of the resistance include Kay, Ryu, and Chiyoko. Among their superiors is the blind Lady Miyako--a powerful religious leader with precognitive gifts.
The Colonel has a number of psychic children under his control. Takashi, Masaru, and Kiyoko are identified by numbers marked on their hands. Lady Miyako was, at one time, Number 19. Number 28 is Akira, so powerful that since the war he has been suspended in cryogenic sleep.
The Colonel's staff conducts experiments which awaken tremendous telepathic potential in Tetsuo, who is redubbed Number 41. Able to shrug off the most serious injuries, Tetsuo goes on a killing spree, even attacking Kaneda. Tetsuo seeks out Akira, whose powers he thinks may rival his own. In hibernation, Akira's power responds to Tetsuo's psychic energy. When Tetsuo reaches Akira's resting place, the cryogenic chamber cracks from within and Akira emerges.
The Colonel summons the powerful SOL military satellite and orders that its laser cannon be fired at Tetsuo and Akira. Akira is saved by Kaneda and Kay, but the laser strikes Tetsuo's left arm. Afterward, Neo-Tokyo is placed in a state of military emergency. "Caretaker robots" patrol the streets and keep order.
Akira and the resistance fighters are cornered by the Colonel's troops, and Takashi takes a stray bullet through the skull.
The trauma of Takashi's death galvanizes Akira. He unleashes a light blast powerful enough to devastate the entire city. Masaru and Kiyoko sweep most of the people in the area upward. Kaneda is last seen vanishing toward the sky. Afterward, Lady Miyako opens her temple and offers shelter and comfort to those in need.
Neo-Tokyo is completely cut off from the outside world, and in the western part of the city the Great Tokyo Empire is formed--a monarchy with Akira as the figurehead and Tetsuo as his Prime Minister. Together the pair use their powers, healing the sick, wielding control of the faithful, and organizing their subjects into fighting units to defend their land. The Empire is eventually infiltrated by teams of spies from the outside world.
Masaru and Kiyoko are sick with withdrawal from the drug which augments and channels mental powers. Lady Miyako asks that Kay bring the psychics to her.
Tetsuo forces an orgy of sex and drugs on several young girls. Only one--Kaori--survives. Afterward, Tetsuo looks into Akira's mind and emerges a terrified wretch. He consults Lady Miyako--whose mind he also briefly touched. She recounts to him the experiments decades earlier which created the numbered psychics and reveals that the Third World War was begun by a mental blast from Akira. She also warns Tetsuo that he alone can control Akira's near-inconceivable powers, but that he must first overcome his dependency on drugs. Disgusted and perplexed, Tetsuo departs. On returning to his stronghold, he neglects his duties of state, concentrating instead on trying to kick the habit.
Kay and Chiyoko try to move Masaru and Kiyoko to Lady Miyako's temple. They are attacked by Tetsuo's followers, who escape with Kiyoko. Chiyoko rescues the girl, but is severely wounded. The two are brought to safety by the Colonel, who has been living in isolation. Before the Colonel departs in a caretaker robot with Kiyoko, Chiyoko, delirious, tells him to take the child to the temple. Meanwhile, Kay safely conveys Masaru to the temple.
Ryu and Yamada watch the Empire from hiding and are startled by an encounter with Tetsuo, whose withdrawal causes his powers to surge erratically. Ryu is even more startled when Tetsuo blurts out what his telepathy has shown him--that Yamada has come to assassinate Akira.
Tetsuo's Lieutenant--acting without authorization--leads his army to Lady Miyako's temple, where they slaughter monks, penitents and helpless refugees. They are defeated by the power of Lady Miyako's psychically gifted monks and Kay's quick thinking. As the Empire's forces begin a new attack, Tetsuo returns to the shrine, maddened with the pain of withdrawal. The Colonel, who has been wounded by soldiers of the Empire, reaches the shrine at the same time and uses a remote control that enables him to fire a blast from the SOL satellite. Tetsuo unleashes a wave of devastating psychic power, driving off his own army. During the mayhem this creates, Kanedareappears, as if from nowhere.
Tetsuo takes another inner voyage, reliving both the happy and painful episodes from his past. He sees a vision of the double helix spiral that Akira constantly creates when he plays. Only Kaori is there to see Tetsuo return to the Great Tokyo Empire and bow down to his young lord.
Aboard an American naval vessel, an international conclave of scientists assembles. They pool their knowledge of the Akira and codename him Juvenile A. Their data indicates that the effect of Akira's power is like that of the Big Bang--the force that created the universe--and that the most recent blast (Tetsuo's) lacked the scope and dimension of the earlier ones. They also theorize a link between the psychic blasts and the firing of SOL, which is now, once again under military control.
Kaneda complains to Kai--a member of Kaneda's old gang who's been helping Kay defend Lady Miyako's shrine--about his ragged clothing. Kai leads him to a black market shop in the local thieves' quarter.
Leading the thieves is Joker, former leader of the Clown motorcycle gang, who were Kaneda's most bitter enemies. However, Kaneda, Kai and Joker agree to work together and avenge Tetsuo's crimes.
The Colonel, too, is after Tetsuo, blaming himself for the destruction Tetsuo has created. Kay badgers the Colonel, hoping to make him reveal Chiyoko's whereabouts. Instead, the Colonel convinces Kay to join him, and the pair leave the shrine together. Lady Miyako is irate when she learns of this, and sends for Kaneda. She implores him to return with her "beloved daughter." Kaneda and Kai agree, "borrowing" a prized pair of motorcycles from Joker to speed their search, and Kaneda confesses that he has been hearing Kay's voice, telling him where she's gone, perhaps through psychic means. The pair take to the subways. They confront an eerie spectral vision of Kay, similar to a vision Kay once saw of Kaneda.
Kay and the Colonel--still weak from his injuries--are harried by a giant psychic and soldiers for the Great Tokyo Empire, but safely reach the Colonel's headquarters ahead of their enemies. There, the doctor and Chiyoko, who is still unconscious, are being guarded by a caretaker robot. When the enemy arrives, Kay and the Colonel use subterfuge to mislead and harass them, and in the midst of the battle, Kay realizes that she can use the caretaker to carry Chiyoko to safety. Meanwhile, the giant psychic finds Chiyoko, and the Colonel finds himself out of bullets.
The Emperor Akira sleeps on his throne, but there's no rest for a world still reeling under the impact of his terrible and awesome powers. No lull for the covert agents planning their secret battles on Neo-Tokyo's broken rooftops. No quiet for Kaneda and the Colonel fighting against howling madmen and thundering weapons' fire. No peace aboard deadly warships playing host to baby-faced assassins come to do their governments' dirty work. Yes, Akira sleeps...but for the world, there's no calm against the storm he has set in motion.