On the day of the coronation of the new king during the Vampire Ghost Festival, the baby girl, who was a noble princess, accidentally "gloriously" tarnished the innocence of the new generation of kings, and the Lord threw her into the world in anger.
An adventure of a baby girl landing
Secondly, the new generation king was defiled and was not allowed to marry anyone other than a baby girl, so he had to go out of the world to find a "marriage" in person.