I'm not entirely sure as I haven't read it specifically. But generally, in tales like this, it might involve a journey of a character, a moral lesson, or a series of events that lead to a certain discovery.
Well, Tale of Tales could be based on a combination of classic fairy tales and mythological elements. However, identifying the exact stories it's derived from is tricky as it might blend and reimagine multiple sources to create a unique narrative.
The 'Tale of Chunhyang' is a famous Korean folk tale. Chunhyang was a beautiful and virtuous girl. She fell in love with a nobleman's son, Mongryong. They got married secretly. But then Mongryong had to leave for Seoul to study. While he was away, a new magistrate came to their town. The magistrate was cruel and lecherous. He tried to force Chunhyang to be his concubine. But Chunhyang firmly refused, staying loyal to Mongryong. In the end, when Mongryong returned as an important official, he punished the magistrate and reunited with Chunhyang.