Ha Ji Won.
One of the first Korean movies I watched after My Sassy Girl is Ditto. I watched Secret Garden too and that sit-up scene is just insane. And yes, I also saw 100 Days with Mr. Arrogant, Daddy Long Legs, and Sex is Zero but the first thing I did in Quiapo after I saw Ditto on Arirang TV is to get a copy of it.
Kim Ha Neul and Ha Ji Won looked alike and it's insane that the three lead characters of the film have guested on the show. Kim Ha Neul was part of Season 1's Actress Special while Yoo Ji Tae is Kim Jun Ho's friend in his Inmates Special.
Now a different Ha Neul came with Ha Ji Won in this special but he's also a high-profile actor in Kang Ha Neul. In Running Man and most recently, 2021's House on Wheels: For Rent, he showed his comedic side as the naive handsome guy. Coincidentally, his castmate Han Hyo Joo also appeared in Season 3.
And of course, their other The Pirates castmate Lee Kwang Soo is probably going to get the ire of Running Man fans if he decides to show his face in the series. I am not hating on the possibility but personally, I would rather see Kwang Soo return to Running Man than get flak. Well, Kim Jong Min appeared in the Running Man spinoff, Outrun... and throughout the years we have seen the likes of Lee Seung Gi, Eun Ji Won, Cha Tae Hyun, and others guest in Running Man (there even talks that Kang Ho Dong is going to replace Kim Jong Kook and Song Ji Hyo) but unless there is a true enough collab between the two programs, I just can't see them going to each other's programs unless it's a web series.
Anyway, Kim Jong Min is the only member to meet all these guests because he's the program's resident dinosaur.
And here's the other thing about Ha Ji Won's appearance.
Na In Woo, the youngest and less seasoned member, is going to be part of the Ditto remake and this probably explains why he froze and ran away at the sight of Ha Ji Won.