On 29 September 2014, Chrome Entertainment officially announced the name of the Crayon Pop sub-unit, Strawberry Milk, composed of identical twins Choa and Way. Chrome Entertainment stated, "Ever since Choa and Way joined Crayon Pop, we always thought it would be fun to form a twin unit group... Choa and Way both like milk, so we came up with the idea of including 'milk' in the unit's name, and as strawberry milk fits the team's image, we decided to name the unit 'Strawberry Milk.'" Before the announcement, a contest was held on Facebook for fans to guess the name. The first twenty people who guessed correctly will receive an autographed album.
On 30 September, it was announced that Strawberry Milk's first mini-album would be released on 15 October. The album has four songs: "OK", "Feel So Good", "Hello" and "Let Me Know". The title track, "OK", is an "unplugged dance number with rock sounds" and "Let Me Know" is a ballad written by Way
