Gong Yoo lost weight to portray his dying character in movie Seo Bok

South Korean film Seo Bok revolves around former agent Ki-hun (Gong Yoo), who has been tasked to protect the first mutated human clone Seo Bok (Park Bo Gum). Gong Yoo talks about how he prepared for Ki-hun, who “has survived many painful days”, what he thinks about working with Bo-gum, and what he learnt about life and humans after this film.