This film is banned in Vietnam, where parts of it were shot in Ho Chi Minh City, as 'containing too many violent scenes'. There is speculation that the screening ban was imposed because of the negative image of Ho Chi Minh City being depicted as a lawless zone where Korean criminals do not hesitate to kidnap and murder tourists.
Kang Hae-sang's four-character tattoo on his chest means 'Cannot allow (oneself) to live (with someone) under the canopy of heaven', or in short 'Irreconcilable enemy'.