The recent episode of "Running Man" featured an unexpected appearance of "2 Days 1 Night" star Cha Tae Hyun. The episode which was aired on March 19 became, even more, a star-studded event with the participation of several South Korean stars including Park Bo Gum, Song Joong Ki and Jo In Sung.

"Running Man" episode 342 started with a mission for the six cast members. They were asked to complete the items that they have listed for their new safe house. One of the show's casts, Kim Jong Kook, seek the help of his best friend, Cha Tae Hyun, who is apparently on "Running Man's" rival show, "1 Night 2 Days". Despite their closeness, it seems quite impossible for the two celebrities to guest on each other's show given its same Sunday broadcast schedules. However, Cha Tae Hyun was able to do a quick appearance on the show in response to his long time friend's call for help.   

Cha Tae Hyun can't physically appear on the show so he had to put on a mask instead of making his face blurred, which he mentioned would be a difficult job for the "Running Man" staff. This episode marks Cha Tae Hyun's first ever appearance on the rival show. The actor first joined "1 Night 2 Days" in 2012 as mentioned in an article published by Allkpop.  

Aside from Cha Tae Hyu, Lee Kwang Soo made the show even more special when he was able to get his showbiz friends Jo In Sung and Song Joong Ki participate in the recent "Running Man's" episode. He contacted both actors via phone for help. Meanwhile, "Love In The Moonlight" star Park Bo Gum whom Lee Kwang Soo unexpectedly ran into was also seen in episode 342. Fans were all excited to see Park Bo Gum on the show. Prior to its broadcast date, the actor's appearance was already reported by Donga