T + Tik Tak Tok by 실리카겔 (Silica Gel)
I recently discovered this song on Youtube; I was
drawn to it based on the thumbnail, which is actually how I've found a lot of good music! (see Locket by Crumb and Give Up by FKA Twigs) It's only after I started listening that I even realized So!YoON! - the vocal of SE SO NEON - was a feature. Woohoo! It's insanely catchy, and WILL get stuck in your head.