Gong Ji-cheol, better known by his stage name Gong Yoo (Korean: 공유), is a South Korean actor. He is best known for his roles in the television dramas Coffee Prince (2007), Guardian: The Lonely and Great God (2016–2017), and Squid Game (2021–present), as well as the films Silenced (2011), The Suspect (2013), Train to Busan (2016), and The Age of Shadows (2016).

One Fine Day is a 2006 South Korean television drama series starring Gong Yoo, Sung Yu-ri, Namkoong Min and Lee Yeon-hee. Originally set to be a faithful adapted of the manga series Flower of Eden by author Yuki Suetsugu,the series was rewritten following plagiarism accusations against the author. The series aired on MBC from May 31 to July 20, 2006, on Wednesdays and Thursdays at 21:55 for 16 episodes.