The hero is a mixed-blooded child with an alien. A very brave boy.
A pretty and smart younger sister, pursued a weak and strong brother, followed a legendary Dragon Flame to protect the world peace, and went on an adventure trip.
No one stopped the three of the orphans.
Their father died in the land of the remote area. It was said that his last days were brave.
Each mother was different, everyone passed away at birth and died.
It is said that everyone was a tragic last.
Eventually the three adventurers got a Dragon Flame that would bring eternal peace to the world after the great success of getting rid of monsters and saving the prisoner's princess.
However, as soon as they tried to take home, that flame had disappeared.
It is a legend.
Originally it was not an area of human knowledge such as eternal world peace.
As a result, the grounds for world peace have disappeared and the wretched world split war broke out by the three people.