After being discharged, Mun's first project was supposed to be KBS' action drama Poseidon opposite Kim Ok-bin, set for broadcast in July 2011. However they dropped out when production was halted after the Bombardment of Yeonpyeong incident in November 2010. Instead, he appeared in another KBS drama, Spy Myung-wol with Han Ye-seul in July, playing a Korean wave star who is at the center of a kidnap plot by North Korean agents.
On July 1, 2011, Mun became CEO (with Lee Min-woo as co-CEO) of Shinhwa Company, a joint venture agency for members Shinhwa to perform as a group. The Company manages the group as a whole, whilst members' individual activities are managed by their respective agencies.
As part of Top Class Entertainment he produced girl group Stellar, who debuted in August 2011 with the song "Rocket Girl".