On July 16, 1988, a catastrophic atomic explosion devastates Tokyo, leading to the rise of Neo-Tokyo, a grim and violent city by 2019, 31 years after World War III. In a dilapidated part of this urban sprawl, a bar buzzes with tension as the bartender, Yôsuke Akimoto, deals drugs while the news broadcasts highlight the rampant unrest stemming from widespread unemployment and economic despair.
Amid this chaos, Kaneda (Mitsuo Iwata), clad in a striking red biker suit, enters the scene. He gathers his friends from a back room, announcing their plan to confront their rivals, the Clowns, on Route 5. Outside, a younger teen named Tetsuo (Nozomu Sasaki) admires a technologically advanced red motorcycle. Kaneda, the leader of the Capsules biker gang, teases Tetsuo, insinuating that he lacks the ability to ride the bike, further fueling the tension among the youth. As the gang rides out into the night, they encounter the Clowns, resulting in a high-octane chase through the city's skyline where violence escalates, and bystanders helplessly witness the wreckage.
During this encounter, Tetsuo suffers a severe crash, just as a bloodied man leads an enigmatic green-skinned figure through the streets. When the man is shot by police amidst a shattering protest, chaos ensues as the green entity flees, evoking panic in the crowd. A mustached man, later revealed to be Ryu (Tesshô Genda), and a young woman named Kei (Mami Koyama) become separated in the ensuing turmoil.
Meanwhile, Kaneda's squad continues their pursuit of the Clowns, but Tetsuo veers off on his own and nearly comes face-to-face with disaster when his aggression towards a downed Clown is interrupted by a shocking encounter with the green entity. A helicopter’s armed paramilitary forces descend, taking Tetsuo to the hospital while Kaneda and his gang face arrest.
At the police station, Kaneda and his companions concoct a flimsy alibi to secure their release. Kaneda's attention is drawn to Kei, locked up with other suspects, and he seizes the opportunity to rescue her, completely unaware of her affiliations with a terrorist organization. Before they can escape completely, an explosion rocks the police station, intensifying the bedlam.
In a parallel narrative, Tetsuo undergoes a body scan at the hospital. Dr. Onishi (Mizuho Suzuki) discovers that Tetsuo possesses psychic abilities akin to those of Akira, an esper responsible for the earlier destruction of Tokyo. Fearing the potential chaos Tetsuo could unleash, Colonel Shikishima (Tarô Ishida) receives orders to eliminate Tetsuo should he become too powerful.
After escaping from the hospital, Tetsuo seeks out the Capsules gang’s hideout. There, he proposes a new life with Kaori (Yuriko Fuchizaki), but tensions flare when they encounter the Clowns once more. Following a fierce fight assisted by Kaneda and the gang, Tetsuo begins experiencing debilitating migraines that lead to frightening hallucinations, along with a sinister whisper—“Akira.”
With chaos erupting throughout Neo-Tokyo, followers of the Resistance, led by Ryu and Kei, engage in high-stakes strategies to fend off government forces while Tetsuo grapples with his increasingly volatile powers. Amidst personal battles and external chaos, Kaneda refuses to abandon his friend, determined to save Tetsuo while also discovering the dark truth that can only lead to destruction.
As Tetsuo descends deeper into madness fueled by his overwhelming psychic abilities, he discovers Akira’s cryogenic chamber, igniting a series of explosive confrontations. Intent on wielding the full extent of his powers, Tetsuo's actions result in brutal consequences for himself and the city. As Colonel Shikishima struggles for control and Kei fights against Tetsuo's might, the final showdown looms on the horizon.
In a spectacular climax, the memories of their shared past ripple through time and space, leading Kaneda and Tetsuo to an explosive confrontation that leaves a mark on both their destinies. The aftermath of their epic battle results in the destruction of Neo-Tokyo, but also unveils a new beginning.
Finally, Kaneda reunites with Kei and Kai as they ride away from the devastation. Somewhere in the void, a voice resonates, "I am Tetsuo," signaling the birth of a new universe amidst the echoes of the old.
