The group was composed of Super Junior's Heechul and TraxX's Kim Jung-mo.

Both members decided to write and compose every song the project group released.

[4] M&D released their debut digital single "Close Ur Mouth" on June 22, 2011.

Island's Choi Jong-hoon and Lee Hong-gi, Supreme Team's Simon D, Miss A's Jia, Beast's Yong Jun-hyung and Comedian Kim Kyung Jin.

[5] Their first live performance was at Mnet’s summer awards ceremony 20’s Choice on July 7.