Joo Won Kyu is the writer behind a book called "Made in Gangnam" (메이드 인 강남). This novel exposes the harsh reality of clubs in Gangnam. The book has revealed everything he learned about the areas club industry, during the 6 months he worked there. He worked as a delivery man and “call girl carpool driver” for half a year in order to conduct research for his novel. The novel was initially ment to be an expose but he decided to change it into a fiction, because no one believed his findings to be true.

He had decided to write this novel after meeting runaway teens. He had interviewed about 90 kids 4-5 years ago, and over 80 of them wanted to work at a club in Gangnam. He became determined to find out why. "The girls wanted to make 5-10 million won ($4,400-$8,800 USD) a month and the guys wanted to become a procurer [pimp]."  ㅡ Joo Won Kyu 

The culture that he discovered in the industry was beyond imagination and he expressed hope that the Burning Sun scandal will help to create justice in society. According to Joo Won Kyu, Sungri’s Burning Sun scandal was only the tip of the iceberg. He says that drug parties, prostitution and police collusion is far worse in reality. There are countless cases of underage prostitution in the clubs and he recalled that there was even a 6th-grade girl among the call girls. Meaning that she was only 12 years old in international age. 

Most aren't as young as 12, but a big portion of the girls being sold are minors. A lot of runaway children is pushed into prostitution when they are living on the streets and the night life industry uses them to make money. Gangnam club owners made these underage girls take date rape drugs before selling them, filming them in secret and used it as blackmail.

"A club owner in his 20s putted minors in a club and made them take GHB. He then approached rich men and sold these underage girls, by faking their age. They then often took videos and used it to blackmail the men. There are streets in gangnam filled with apartments just devoted to illegal prostitution."

Joo Won Kyu also exposed to MBC that some clubs even made snuff films, and women who endured these “events” would be paid 100 million won ($87,963) for doing it. "A snuff film is a video of a real-life rape and murder incident that would be re-enacted" (a snuff film is supposed to show a real rape or murder, but this is what they wrote).

Just like Seungri was the face of Burning Sun, many celebrities have invested and are shareholders of these clubs. "As Gangnam clubs began to grow into a huge industry of its own, idols often became shareholders of the major clubs. Members of the idol group S hold shares and numerous celebrities under the large entertainment company Y are participating as shareholders." ㅡ Joo Won Kyu

He also discussed professional methods to rid the system of drug use in the industry. "When I worked 3 years ago, tourists from Southeast Asia came to do drugs and hang out at the clubs. They even had professional means to avoid drug detection. They would cleanse the stomach or take other medication to dilute it." ㅡ Joo Won Kyu

The writer won the Hankyoreh Literary Award in 2009 for "Outrageous Race" (열외인종 잔혹사) and wrote the TVN drama "Argon" in 2017.

Disclaimer: This is information based of an interview MBC conducted with Joo Won Kyu about the industry, this haven't been proven true with any evidence yet. It should also be kept in mind, that the writer isn't claiming that the celebrities reported in the news were behind these clubs, he only named the persons behind these clubs as "celebrities" from idol group "S" and company "Y". You can read the article here.