Every once in a while, a plague breaks out in this world. At this time, the country will select the strongest magician to summon a "saint" to purify the plague. And the saints all come from another world. Saints learn magic.
After completing the purification ceremony, the saint will choose a partner among these princes to accompany her for life.
When the plague breaks out again, the country still chooses to summon the saint this time, but this time it is different. There is also a very good-looking "little boy" summoned together.
Purpose: Fight against exploitation