The story features inhabitants of Earth and Mars waging in an interplanetary war. The story touches upon the effects wars have on a country's government and its people.
War is coming...
The two powers will soon clash with one another and by military force, start killing each other.

Humanity has clearly split into two and currently there is no way these groups will once again unite. Humanity celebrates this transient time of peace as they slowly dismiss from their minds the scars their ancestors bore in the past. No one realized that with one little push their world canfall to its destruction.

Just one little spark will do.
Preparations are steadily on its way.
Then we shall see the end to this false peace.

But, there are men who realize the approach of this inevitable war. Most of them are close to the military. Though, of course these men are well aware that they have no power to remedy this situation. For that is why they are deep in despair. Among the soldiers that I have had contact with, there were even men who were depressed when they realized the impending war. Even then, as far as the people of Shinawara City, I did not feel that any of them had any sense of danger. While in their minds, they knew that war was unavoidable but they could not help but to continue living each day as if nothing was changed. That is all I can say about that. Humanity has grown too used to this false peace.

Humanity does not go to war because they know that they possess a clear sense of justice within their troops. Also, they do not declare war because they are confident of their own victories. The reason man goes to war is simple. War exists simply because there are men who wish to wage

We just need one simple reason.
For that reason, our plans are right on track.
There is no way of avoidance.
I will say it once more.
War is coming.

(Source: Aniplex USA)