Actor So Ji Sup (36) made a surprise appearance in MBC entertainment program "Infinite Challenge."

So Ji Sup starred in the episode of "Infinite Challenge" which aired in the evening of Saturday, December 14, 2013. Afther So Ji Sup received a call from Jung Joon Ha, one of the hosts and fixed members of the program "Infinite Challenge," he met up with Jung Joon Ha and the other hosts of "Infinite Challenge" You Jae Suk, and Noh Hong Chul.

So Ji Sup said he has been resting since his SBS drama with Gong Hyo Jin "Son Of The Master" has ended in early October. His showed a different appearance, with the mustache. Although he was not wearing any makeup, his appearance was incomparable with that of Jung Joon Ha and Noh Hong Chul, who had done full makeup before filming of the "Infinite Challenge" program.

The "Infinite Challenge" could not hide their excitement and greeted So Ji Sup with hugs.

So Ji Sup, who realized that the members of the "Infinite Challenge" are casting celebrities for their special program, "Introducing My Lonely Friend," said, "I am never lonely." However, the members tried to recruit So Ji Sup saying, "You do seem lonely."