Coed School was a South Korean pop group formed by Core Contents Media in 2010, known for its lineup comprising four female members (Soomi, Hyoyoung, Hyewon, Chanmi) and six male members (Taewoon, Sungmin, Jungwoo, Kwanghaeng, Kangho, Noori). This "co-ed" lineup was unusual for the world of Korean pop. The group later branched into two sub-units: F-ve Dolls, an all-female group, in 2011, and SPEED, an all-male group, in 2012. The group made their initial splash with their debut single "Too Late" in 2010, followed shortly by "Bbiribbom Bberibbom." The latter single peaked at number 61 on the Circle Chart. They released their debut mini-album, Something That Is Cheerful and Fresh, in 2010, peaking at number 8 in South Korea. Despite a production limit of 20,000 copies, it received 50,000 pre-orders, leading to increased production. In 2011, the female members of Coed School formed the sub-unit F-ve Dolls, debuting with the single "Lip Stains" on February 7, 2011. The male members debuted as SPEED in early 2012 with the digital single "Hommage to Lovey-Dovey." By mid-2013, Core Contents Media indicated that there were no plans for Coed School to promote as a full group due to the evolution of its sub-units. By late 2014, all members, including those in the sub-units, had left the agency.