Akira is the product of government-military experiments in Japan to awaken psychic talents. He is actually experiment test subject 28.
His power was extremely uncontrollable and the psychokinetic explosion he created was so powerful that it bent both matter and energy literally vaporizing Tokyo more powerful than any known nuclear detonation.
Somehow after the event, the Ministry of Defense were able to capture the young boy and place him in cryostatis deep within the research facility underneath what became Neo-Tokyo.
Akira with Tetsuo and the other experimental children apparently created a new universe in another dimension.
World War III
Before being captured in cryostasis, he created the explosion that wiped out Tokyo and sparked World War III.
Akira is quietly mysterious.
Akira is the most powerful psychic known to have manifested.
Psychokinesis - even the smallest psychokinetic blast is enough to vaporize many city blocks.