500 years ago, the human and demon realms were divided, causing demons to all but fade from memory. That is, until young Lady Yeonri frees the King of the Dokkaebis, Mujin, from the seal that bound him. Grateful, Mujin pledges to protect Yeonri and bless her clan with eternal prosperity… but as Yeonri grows up with Mujin at her side, she realizes that there’s actually something more she’d like from him…