It is strange. I do not see the storyline at all for the moment. The directing seems hesitating, the editing also.
Storywise, we only know Sun got a heart disease than seems untreated, Kim is emotionless (which for a musician is impossible unless a robot is playing the instrument), Kim's father is an antagonist, Payoo Rain could be a side couple.
But I don't know where we are heading for, I will wait, there is 14 episodes, it seems to be a slow setting up.
Just for funfact, the appartment os Sun is the same as Khabkluen in Star in my mind.