When you were a child, you became a hero by killing herrscher of Finality aka kiana, however, kiana's girlfriend mei saw, and "You killed the person I love, so I will give you a curse that, at the age of 16, you will fall in love with someone." said then Mei left 10 years later, she came back "I want to see your miserable appearance she smiles evilly, she wants you to suffer for love like you did to her girlfriend kiana