It's practically a boy band rite of passage to mature from a cute and bright image to a harder, more aggressive one, and BOYFRIEND is no exception. They set the tone for their early career with the eponymous debut single, a peppy dance-pop number with the chorus: “I'm your boyfriend, you're my girlfriend.” Their singles have since crossed into darker territory, incorporating hip-hop and rock as well as less happy themes like jealousy and breakups. But their continued output of sweet love songs shows they haven't forgotten their “girlfriends.”