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 Chiyoko.
The Colonel had a number of psychic children under his control. Each is identified by a number marked on the hand. Among them 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 the Third World War with a mental blast. He was recently reawakened by the jealous and ambitious Tetsuo. Shortly thereafter he responded to an emotional trauma by again devastating the reconstructed city of Neo-Tokyo. Japan now exists in a state of emergency. The forces of the army and the resistance 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. Most faithful among their numerous followers are Tetsuo's dapper, ambitious assistant and his friend Kaori. Their headquarters are Neo-Tokyo's Olympic Stadium. To the east, Lady Miyako welcomes refugees, including Kay and Chiyoko, 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 from the outside world, but all of them except Lieutenant Yamada--who takes temporary shelter with Ryu--are killed. Ryu wants to join Yamada, until he learns that the spy plans to assassinate Akira even if it means taking innocent lives. After that, Ryu keeps an eye on Yamada, trying to protect both the invader and the people of Neo-Tokyo.
Aboard an American naval vessel, an international conclave of scientists studying the Akira phenomenon learns that the world's armies have amassed an Akira Assassination Corps, despite their recommendations. They are aghast to learn that, to stop Akira, the military is willing to destroy all of Neo-Tokyo and its citizens, if necessary. 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. Lady Miyako explains that Akira's personality has been destroyed by his power, leaving him a passive vessel, and that when Tetsuo's character is likewise eroded, he too will be beyond control. Remembering that, on a whim, Tetsuo recently destroyed part of the moon and set off geological cataclysms, Kay agrees to join them.
Kaneda, who's teamed up with Kai and Joker--a friend and rival from his gang days--is outraged to learn of the risk that Miyako has talked Kay into taking. He vows to kill Tetsuo himself rather than let her face such danger. He, Kai and Joker formulate an strategy involving most of their men as well as the state-of-the-art weapons they've salvaged, including laser rifles, flying platforms, and one caretaker robot. Together, they head for the Olympic Stadium.
Following his huge expenditure of power, Tetsuo begins to lose 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.
Yamada and his men meet one of Tetsuo's trained psychics--the Eggplant Man. To their dismay, they find that he can withstand gunfire...and kill without touching. However, they are able to distract him long enough to kill him, and then eliminate Tetsuo's other trained psychics with biochemical weapons, saving their deadliest germs for use against Tetsuo.
Soon after, the Colonel also reaches the stadium, determined to kill Tetsuo, who he believes could become another Akira. He manages to fire one blast from SOL before outside military forces seize control of the satellite by computer. Then, Joker arrives on a flying platform and strikes Tetsuo, causing him to mutate again.
Kaori, still loyally trying to find someone to help the boy she loves, learns that Tetsuo's former assistant is now planning to betray and murder his former master. As she runs to warn Tetsuo, the traitor shoots her in the back. Tetsuo, his mutations temporarily in remission, comes upon her as she dies.
Inside the roiling vapor of a deadly germ warfare cloud, weapons fire ferocious charges of lightning-like destruction, a hi-tech storm warning of the man-made tempest that continues to assail what's left of Neo-Tokyo. It rumbles deep and dark as American troops in bio-chemical warfare suits march omniously through shattered canyons that were once city streets. It flares bright with explosions of raw energy and telekinetic fury, former friends now turned adversaries competing in a most dangerous game of hunter and hunted. And at the storm's center, an eerily composed Tetsuo, his icy calm making him even more sinister.