EXO-CBX talked about forming the sub-unit on the November 2 broadcast of 'Cultwo Show.'

Regarding why they formed the unit group, Baekhyun said, "We work out together, and the trainer said that the three of us have similar heights and would do well if we [did a group] together.  That's why we actually suggested that to the company and ended up making this unit.  We made the name something easy for the public to say.  We tried rearranging the order [of the letters], but CBX seemed the best."