EXO-CBX is the first official sub-group of South Korean-Chinese boy group EXO, formed by SM Entertainment in 2016. The unit is composed of three EXO members: Chen (첸), Baekhyun (백현) and Xiumin (시우민).
After the trio released a song for the drama Moon Lovers: Scarlet Heart Ryeo titled "너를 위해 (For You)", fans began to speculate that they would form EXO's first sub-unit. SM Entertainment confirmed this on October 5, 2016.
Their first album Hey Mama! was released on iTunes and other music service sites on October 31, 2016. The group made their debut performance of the title track "Hey Mama!" on M! Countdown a month later on November 3. Hey Mama! topped the Billboard World Albums chart and South Korean's Gaon album chart. Later in November, EXO-CBX recorded a remake of the original soundtrack "Crush U" for the game Blade & Soul.
On March 10, 2017, it was revealed that EXO-CBX would make their debut in Japan in May. On April 1, the group was announced to be releasing their debut Japanese extended play Girls on May 24, 2017. The extended play's title track was "Ka-CHING!".