A YouTube algorithm led me to this Danish singer.
The song is really good, and the comments are very funny.
Korean fans call like this comments '주접댓글' with love for their idols.
I recommend watching the Korean fans "떼창(Singing along with the song)." too.
Since elementary school, Koreans have been trained(?) a lot at retreats or karaoke rooms.
Get in at the right time and get out at the right time!