Seiketsu no Haguruma

Two peoples, one with red blood and the other with blue, once live together peacefully before hatred drives them into war. The larger red-blood army gains the upper hand until Kodo, prince of the blue-blood people, develops the Haguruma: powerful machines capable of devastating destruction. Their use turns the tide, and the blue-blood people win. Afterward, the red-blood people are enslaved, hunted, and killed. Seeing the horror his invention enables, Kodo rescues red-blood refugees and refuses to build more Haguruma. His father, the king, orders his execution, but Kodo narrowly escapes. Now without a home, he must survive on his own.