Starting with this one:
I only know two people from this combo. Si-kyung and Hyo-Shin. That's pretty much about my K-pop knowledge for me. But this is a pretty cozy song with a nice combination of various singers (and a rapper).
Up next is Sweet Sorrow, a four member a capella vocal group.
I do have to admit, this is really cute. And gosh they're so adept with their voices. I give applause to their ability to harmonize into such vocal richness.
Next are some big names among Korean singers. Kim Bum Soo, and Lena Park.
Anyways, I was surprised to find original Christmas songs from K-pop. Often artists just rehash old carols, but Koreans are awfully inventive. Hope you found these cozy enough to get you into the holiday spirit.