It happened before but The Great Master had stopped it. Although he wasn't able to end the curse, he stopped it for 100 years before it returned. He left a message for us to prepare for the Blue Moon Years and a school was created to find The One who will be able to end the curse of the Blue Moon. Even if the intention of building the school is to find The One, greed still wins. People still want the strongest slaves for themselves. 1,000 years had past since the Blue Moon appeared again and

If all these years you listen to stories of a mermaid saving a prince's life and she end up falling in love then, you tell the same exact storyline to the kids to make them stay quiet while babysitting them, you need to prepare your mind for a  different storyline and try to accept it even if you think that it's way better having the original storyline.  This is a story of a mermaid falling in love with a human boy after being saved by him. The boy moved to Seoul and convinced himself

They were seperated to protect the kids, to protect their future. They had both agreed to it. They had been living well even if seperated from the other. They just need one call  every night to cure their longing for each other. This story is one of the many phone calls between the two separated lovers.

Kim Jun Myun and Kwon Ru Mi made a promise as a kid that they will be best friends till the end of their life and keep their brother-sister relationship even if they are married to their love ones before she move to Jeju Island. They even promised not to marry each other if it is an arranged marriage set by their parents because they know how their moms are. After 15 years, both of their moms met each other by chance in a bakery and decided to arrange their kid

Kris had a secret. The reason why he left exo. The reason why Luhan left exo not long after him. The reason why he can act easily with Sophia in the movie somewhere only we know. He had a daughter and is currently living a life of a singleparent.