Stigma; A mark that has a special religious significance among the marks on the human body.

Sion is rescued from a village where he was horribly slaughtered when he was young.
While working as an apprentice priest at a temple in a neighboring village, hoping to live a life without curves, he accidentally rescued High Priest Parbellone and, with his favor, ascends to Zeon, the capital of the Holy Kingdom.

5 years after that.
Shion is imprisoned in a dungeon for having 'something not to have', tortured by Holy King Sienas, and dies after learning that he had been betrayed by Parbellone, whom he trusted.

However, the next moment, on the day of the King's coronation ceremony five years ago, Sion wakes up in the body of none other than Sienas...