송강호
"Thirst" had been in the works for a number of years prior to the film's shooting and release. As early as "Joint Security Area", director Park Chan-wook had asked Song Kang-ho to star in a vampire film Park was developing. Park further developed the film's story with co-writer Jeong Seo-kyeong while the two collaborated on "Lady Vengeance" and "I'm a Cyborg, But That's OK".