"The beautiful blue sky is getting painted darker each passing moment. War. People killing each other. No one even knows who started it anymore. No one even knows how long they have been fighting against each other, forgetting what they are fighting for. People have made themselves into weapons to snuff others out, forgetting their dream of flying freely in the sky. The war has been lasting forever. But the end seems to be at hand. The population has seen a massive decrease, and the whole planet as the battlefiled is on the verge of destruction. Knowing all that, people have become weak and keep warring without getting hurt themselves. That way, they are merely postponing the inevitable. During the war, a girl was born. Her name was Sora. She was born with a power for fighting. She was not happy about it, but the people around her were and they sent her to the battlefield with no thought for her feelings at all. The last war on the worn-out planet. Whether it is won or lost, there would be nothing left. Sora did not know the meaning of the fight."