Чан Гын Сок
Choi participated in episode 15 of Seoul Broadcasting System's "Idol Maknae Rebellion" () with fellow band member Seung-hyun, who was a cast member of the show; the episode aired on February 15, 2010. He made his acting debut as a supporting character in the film "You're My Pet" (2011) starring actors Jang Keun-suk and Kim Ha-neul. Based on the Japanese manga "Tramps Like Us", Choi plays the younger brother of Kim's character. The film centers around a woman living with her human pet.