Wonder Girls (Korean: 원더걸스) was a South Korean girl group formed by JYP Entertainment. The group debuted in February 2007 with the single "Irony" and five members: Yeeun, Sunye, Sunmi, Hyuna and Sohee. After Hyuna's departure in July, Yubin was added into the group prior to the release of their debut studio album, The Wonder Years (2007). The album spawned the hit single "Tell Me", which topped various South Korea's on and offline music charts.