"I say mama, mama, mooo~ Hello, we are Mamamoo!" MAMAMOO (마마무) consist of 4 members: Solar, Moonbyul, Wheein and Hwasa. MAMAMOO debuted debuted on June 18, 2014, under Rainbow Bridge World (formerly WA Entertainment) with the single, "Mr. Ambiguous". Their debut was considered by some critics as one of the best Kpop debuts of 2014.
Prior to their official debut, Mamamoo collaborated with several artists. Their first collaboration titled "Don't Be Happy" with Bumkey was released on January 8, 2014. On February 11th, 2014 Mamamoo released their second collaboration with K. Will titled "Peppermint Chocolate" featuring Wheesung. On May 30th Mamamoo released another collaboration with rap duo Geeks called "HeeHeeHaHeHo".
On June 18, 2014, the group made their official debut with the lead single "Mr. Ambiguous" from their first extended play, "Hello". They made their first live appearance on June 19, 2014 episode of Mnet Countdown.