Is there a meaning/message behind Akira? Is there some hidden meaning/message in Akira? 

Does it have something to do with the scars left in the Japanese by the bombings in Hiroshima and Nagasaki? And ultimately...


   is Akira the A-Bomb?


Or is there another deeper meaning than the one depicted in the movie?
The manga is far more informative than the movie. The movie seemed to adapt the first two and the last volumes for its content, without really bothering to explain anything about who characters were and where they came from.

The manga, begins with a nuclear blast that destroy Tokyo and triggers World War III.


   It turns out that it wasn't a bomb, but Akira that caused the blast. Much of the plot of the first half of the manga concerns attempts by the military-industrial complex to contain the power of Akira. The central plot device involved an experiment to create weaponized "psychic" children through neuro-surgery and pharmaceutical regimens. Akira was an experiment gone dangerously awry and the child is now kept deep underground (under Neo-Tokyo's Olympic Stadium) within a sort of giant high-tech freezer.


I believe that there is a taboo on overtly discussing the bomb that speaks to a mediation between repression and remembrance. The memory of a nuclear attack on one's own nation is a bit too vivid of a tragedy for many to face directly. The author makes very good use of  allegories to present a nuclear holocaust through a shounen type of juvenile and imaginative storytelling. This way, a Japanese reader might be able to be drawn into a subject that would otherwise provoke repulsion, or at least unease and anxiety.