wait, why did kenta feels uncomfortable around jun? I still don't get it

Same

I think it’s because he likes him a little. Maybe not romantic, but like a good friend. It was Kenta’s job to take care of Thomas and Minjun is making him very happy, so Kenta feels good about it. But he needs to be serious and stoned face all the time, since he’s still a yakuza. And we all know what happens when someone tries to get all chummy with the Minjun.
At least it’s how I interpreted.