Gong Yoo and Kang Dong Won have been well known to be best friends in the entertainment industry as they often expressed their fondness towards each other.

Recently, it was revealed that these two actors are much closer than people expected. On the Mnet entertainment show 'TMI News' that aired on the 15th, Gong Yoo and Kang Dong Won appeared as two best friends who are as close as family. The show revealed that their grandfathers are also best friends.

MC Jang Do Yeon explained, "It has been known that Gong Yoo and Kang Dong Won have been the best of buddies ever since their modeling days. These two along with Jo In Sung as well are known to be the best of friends." In addition, Jang Do Yeon explained, "They actually have family ties," surprising the viewers. She went on to elaborate, saying, "Kang Dong Won found out while talking to his father over the phone back in 2004. He found out that his grandfather's best friend was Mr. Gong, who is Gong Yoo's grandfather."

MC Jang Do Yeon continued to say, "Their grandfathers introduced the siblings of Gong Yoo's and Kang Dong Won's to each other and they ended up getting married. So, Gong Yoo and Kang Dong Won are now actually in-laws." 

According to insiders, Gong Yoo and Kang Dong Won continued to share a deep friendship as they even recommended each other to films. Director Yeon Sang Ho, who directed 'Train to Busan,' revealed that Gong Yoo recommended Kang Dong Won for the sequel movie 'Peninsula.'