This is a story about a demon who grew up alone and now wants a friend, and a human boy who is discriminated against because he's half mage but with no magic powers thus also friendless.
It's pretty cute and funny, Iver (the demon king) has a very odd idea of humans because he's never been in their world, and Ling Xiao is trying to find a friend for him while having no friendship experience.
This story had potential, unfortunately the author admitted losing interest and rushed the ending. It's still technically a good ending but clearly there wasn't a lot of thought into it and some aspect of the story remain unexplained.