I got introduced to them through my cousin, whose friend apparently used to chill with them a lot before she moved to the US.
장기하와 얼굴들 is the actual Korean name. The blog title is a rough translation. I don't understand all of the lyrics (like maybe 10-20%) but it still makes me laugh.
"달이 차오른다 가자" - roughly "The Moon is Waxing, so Let's Go" I think...
"싸구려 커피" - roughly "Cheap Coffee"
EDIT
The girls in the first video on stage are the Mimi Sisters...they're part of the band's live show, and are basically backup dancers that are just fucking hilarious.