Responses
I just finished the drama and came here to see how each of the characters looked. I only skimmed for a few minutes but I didn't see J's character? Did I miss him in a specific chapter cause I did see Hyunbin and his manhwa character design is very similar to Yoojung's in the drama and he came from overseas, as well. I feel like they divided Hyunbin's character to give out more roles. Correct me if I am wrong since I only skimmed.

I just came over to check out the comic after starting the drama, so I figured I'd leave a bit of a review without actual spoilers for each. ^^
Comparing the comic and drama is not exactly a good idea. Do NOT go into checking the other out with the mindset of seeing one (comic or drama) being simply copied into a different medium, they are MUCH different. Happenings AND personalities and even looks of characters. Which is not exactly a bad thing if you are open minded.
You can take it as baseplots being used by different authors. Kinda like we get BL plots with a scary looking delinquent that's just misunderstood by many due to being socially awkward, so the greatest dude in school finds out and tries to make people realize he's different, while falling in love with the socially awkward tsundere. Or how we get so many shoujo reincarnation plots of a dorky heroine falling in love with the emperor who's disguising himself as a normal person, knight, average noble, etc..
Similar plotline, but each story you read is much different from one another. THAT is basically how you need to go into the drama or comic when you want to check each one out after seeing one of them.
I'd say both are nice in their own ways. The drama does some things better than the comic and vice versa, for different parts. The MC is for example MUCH more likable in the drama than in the comic. Simply because he doesn't come across like an arrogant jackass who insults the 'old washed up idol' immediately upon hearing he's supposed to team up with him, that was a great turn off for me tbh. Yet the female 'villain' is much more dislikable in the drama than in the comic. Coming to realize his feelings is done better in the comic but it works very well as done in the drama. Etc.. There's lots of nuances and different ways things are done, but so far none are bad. It's simply a much different story rather than an adaption.
Pretty sure Hana Kimi had the same sort of difference to it when it comes to the manga, japanese and tai(?) adaptation. Similar but not the same, but each interesting in their own way.