The ancient demon clan, the key to unlocking the demon clan's seal, what is the male protagonist's life experience? How could the heroine, who has a soft spot for music, fall in love with the enemy who killed her father? How could they, who were once gods, end up in the mortal world? Why did she, whose ancestors had been a servant for the same family for seven or eight generations, win the prince's heart? If you want to solve these series of mysteries, you can only use one word - fate.