Am I the only one who's just wondering what happened to the past friendship arc with heemin?? It's been years

errrm honestly i think he was mentioned just to show how hooni was introduced to SH/ why suicde became so normalized in his life

And that's it? There's too many questions and unexplored potential behind it,How did hooni deal with him? How strong is actually their bond? Why does he never show up again despite randomly showing up?