ONF (pronounced as On and Off, Korean: 온앤오프) is a South Korean - Japanese boy band formed and managed by WM Entertainment. Originally debuting as a seven-piece group on August 3, 2017, with their EP, the group currently consists of six members: Hyojin, E-Tion, J-Us, Wyatt, MK and U. The group's youngest member, Laun, left the group on August 23, 2019, for personal circumstances shortly before the group's fourth extended play Go Live.Since their debut, ONF has since released a studio album, a repackaged album, seven extended plays, and two Japanese singles following their Japanese debut on August 1, 2018.

Source: Wikipedia (https://en.wikipedia.org/wiki/ONF_(band))