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 everything is corrupted. Masters look for the EXO slaves who is believed to be the strongest slaves in history and would kill just to get one. Slaves were killed to get a stronger one become theirs since there's a limit to how many slaves a person can have. Although most of the masters are greedy with power, there is a village where masters would like to live peacefully with their slaves. They are usually masters with weak slaves. The village is called village of the beginning since that is the village where the first slave appeared when the Blue Moon appeared. This story is about a girl's journey in the Blue Moon Academy with her slaves.