How the feelings and emotions were expressed

It's one of the best series I have watched in my life. Everything is perfect, the cinematography plus they are such great actors the way they expressed their feelings and emotions, I really love the story. At this rate I'm just hoping for a happy ending and season 2 of course. I'm in love.
And not to forget the osts, I fell more for the actors when I heard them sing these great osts.
Especially Billkin, I watched a video where he performed live and he sings so passionately. Enough for us, fans, to fall deeper.