Long ago there was an orphan girl that was born in the middle of the miserable age. The period when people still fought against the abyssal force. Her name is Laurelin.
She was abandoned by her own family when she was a baby. Thankfully, the group of holy apprentices had found her before those blood-thirst creatures could have eaten alive this little soul. Laurelin is the name that the High Priestess of the Golden Temple named for her. Yes, she had been adopted by kindest people during the age of bloodshed.
The Golden Temple has always been protected by the spirits of the golden bloom. However, to stay in the living realm, they need a successor with a pure heart to possess. And the one with the most undefiled heart can only be the Saintess of the Temple.
So the holy festival is a traditional activity of the Golden Bloom Temple's nuns. It is when everyone witnesses the descending of angels. These saintly beings will pick out the exemplary one.
And the chosen one is Laurelin.