Park Young-Guk is the father of late Kim Young-Guk. He is also a contact of Derrick McReary, who he entrusted to protect Kim when he came in the country with a load of fake hundred dollar bills. Along with him came Niko Bellic, who also later killed Kim on orders of Jon Gravelli.
Park Young-Guk may be based on O Kuk-ryol, a North Korean military general suspected by the US government as a key figure in North Korea's currency counterfeiting activities, it's production of Superdollars and like Kim Young-Guk, involving his son O Se-won in the business. Derrick McReary's relationship with Park Young-Guk's may be further based on alleged business relations between IRA leader Seán Garland and agents of the North Korean government involved in the sale and distribution of Superdollars.
Just like most of the Chinese character names in GTA IV/Chinatown Wars, the name Park is incorrectly used as a given name and Young-Guk as a family name. In Korea, family names are written always first, then the given names. Besides, Park is a very popular surname in Korea.