MAMAMOO (Hangul: 마마무) is a four-member South Korean girl group under RBW. The group consists of Solar (솔라), Moon Byul (문별), Whee In (휘인), and Hwa Sa (화사). They are recognized for their retro, jazz, R&B concepts and their strong vocal performances.

The group made their official debut on June 18 with lead single “Mr. Ambiguous” from their first extended play Hello. The music video for “Mr. Ambiguous” contained cameo appearances from many well-known K-pop industry figures such as CNBLUE’s Jonghyun