Firstly, i always have doubts when it comes to adapting a webtoon. In this particular case, the task is even more difficult since the plot is not easy to follow and the drawing had a particular esthic. I still gave it a chance...

How do you justify turning the story into a musical ?!?! I think it really turned me away from the plot.
There are many ways turn on the magic without putting music into it . Otherwise we could have called disney.
The signing is fine but whimsycal doesn't equal musical.

The plot roughly flollow the webtoon but i think that the personality of the female lead is not what the autor intended. She's ways to much naive/amazed/.. I think she wasn't very likeable

Rearding the cast, the acting is fine. BUT you need to stop asking >25years old to play highschooler it is impossible to believe (especially de FM).

It only last 6 episodes and that was quite enough for me.
You can still give it a try but don't forget to check out the webtoon.