Afterschool is the only K-pop group to operate on an “admissions and graduation” system, where new members get added while others “graduate” to solo careers. The group puts intense hours of study into creating the unique concepts—marching band drumming, tap dance, pole dance—to best present its songs, which mix gorgeous melodies and delicate synth work with pounding club beats. Spin-off unit Orange Caramel is just as creative, and has hit it big with a combo of cartoonish costumes and a hyperactive, Europop sound.