2030. The world hovers on the brink of World War IV. Kaneda, one-time leader of a delinquent gang, is caught up in the aftermath of a power struggle between a Japanese military research organization--led by a man known only as the Colonel--and a resistance group whose members include Kay, Ryu, and a formidable woman named Chiyoko.
The Colonel had a number of psychic children under his control. Each is identified by a numbered tattoo on the hand. Among the children were Kiyoko and Masaru--Numbers 25 and 27. The blind Lady Miyako--Number 19-- was once among their ranks but now heads a great religious cult. Number 41 is Tetsuo, once Kaneda's friend, but now his greatest enemy. Tetsuo lost his left arm to a laser blast from the Colonel's military satellite SOL, and has used cybernetics and telekinesis to fabricate for himself a prosthetic replacement.
Most powerful of all the children is Number 28--Akira--a docile and enigmatic boy who was placed in cryogenic sleep almost forty years ago after he started World War III with a mental blast. He was recently reawakened by Tetsuo, and again he devastated the reconstructed city of Neo-Tokyo. Now Japan exists in a state of emergency. The forces of the army and the resistance are scattered, and the military's formidable "caretaker robots" patrol the streets.
In the western part of Neo-Tokyo, the Great Tokyo Empire is formed--a monarchy with Akira on the throne 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. To increase the Empire's power, Tetsuo uses drugs and training to develop psychic abilities in certain of the subjects. Most faithful among their numerous followers are Tetsuo's girlfriend, Kaori, and his dapper ambitious assistant. Their headquarters is Neo-Tokyo's Olympic Stadium. To the east, Lady Miyako welcomes refugees to her shrine. In this, she is aided by Kiyoko, Masaru, and a number of loyal, psychically gifted monks.
The Empire is infiltrated by teams of spies and commando units from the outside world, led by American Lieutenant George Yamada. Yamada is under orders to assassinate Akira, even if it means taking innocent lives. To that end, he and his men are equipped with biochemical armaments which take a tremendous toll on Tetsuo's trained psychics when the two groups meet in battle.
A fleet of foreign ships waits in Tokyo Bay, poised for action. Aboard an American naval vessel, an international conclave of scientists and one Tibetan monk study the Akira phenomenon--which they've codenamed Juvenile A. One of the scientists--Stanley Simmons--goes ashore without authorization, hoping desperately to implement a secret plan.
Meanwhile, Lady Miyako, Masaru and Kiyoko convince Kay to join them in the battle against Tetsuo, because Kay is a powerful medium, through whom the others could project their powers and strike as one.
Kaneda, who's teamed up with Kai and Joker--a friend and rival from his gang days--vows to kill Tetsuo, using most of their men, as well as such state-of-the-art weapons as they've salvaged, including laser rifles, flying platforms, and one caretaker robot. At the Olympic Stadium, they find destruction and chaos. Their enemy is already under attack by Kay, Yamada's forces, the Colonel, and even by Tetsuo's own men. Tetsuo's lieutenant is so afraid of his leader's power, he tries to flee, murdering Kaori so she can't betray him.
Tetsuo loses control, and his artificial arm assumes a grossly mutated form. He runs amok, killing anyone who comes too close. His power has grown beyond what his body can contain and is now trying to absorb its surroundings. His body begins to alternate between a normal human form and an immense, uncontrollable, bloated grotesquerie.
Tetsuo finds and is mourning over Kaori when his lieutenant comes to him, cravenly pleading for help against Yamada's forces. The lieutenant and his loyalists die horribly, victims of the biochem weapons, while Akira looks placidly on. When Yamada shoots Tetsuo, Tetsuo is enraged, and Yamada dies a hideous death.
Ironically, the germs in the weapon affect Tetsuo like a drug, enabling him to reassert mastery over his powers. A duel in the stadium ensues, with Kay and Kaneda using lasers and telekinesis against their enemy. Kaneda sends Kai to safety with Akira, and Kai hands the boy over to another gang member, hoping to find Joker and return to the fray.
Then, the international fleet in the harbor sends fighter planes to rain death upon Neo-Tokyo.
Ffom high above, Neo-tokyo ceases to be a city of the living, becoming instead a target for the soon to be dead. American bombers drop terrible payloads toward the ravaged streets as weapon platforms dance at the edge of space, firing arcane rays of hi-tech destruction down on a battlefield of men and something more than man. From below, the telekinetic power that is Tetsuo rages to be unleashed anew, promising awesome revenge for this latest attack from nations fearful of the unknowable might that is Akira.
And trapped between the heavens and hell on earth, an anxious humanity all too aware of their own mortality.