The story centers around a winged-species called the "Mulawin" who once helped the humans. However, due to the man's greed, the Mulawins later excluded themselves and hid in the mountains while a rebel band of Mulawins called the "Ravena" formed to seek vengeance against the humans. Aguiluz, a young Mulawin, was tasked by his father to find and protect the "Sugo" who was in the human world.