A cross-border love story sweeps up South Korea

North Korean defector contributes to script.

SEOUL, South Korea -- A surreal love story of a North Korean army officer and a billionaire from Seoul has swept up South Korea, becoming the second most-watched Korean drama (or "K-drama") TV show in the nation's cable TV history.

"Crash Landing on You," begins with a South Korean fashion brand CEO accidentally paragliding into the demilitarized zone. Through a creative plotline, the show provides a detailed portrayal of the isolated North -- a look into the other side of the border.

The cast includes an actress and a writer who defected from North Korea, adding authenticity to the show.

"The theme the lead writer Park Ji Eun wished to portray in the show was that North Korea, too, is a place where ordinary people live," Kwak Moon Won, a show contributor, told ABC News. "Just like us, they have dreams, they share grief. The writer wanted to paint a story of [North Korean] people with warm hearts."

Kwak attended Pyongyang University of Dramatic and Cinematic Arts for 10 years. While there, he participated in the production of the communist regime’s propaganda films such as "Urban girl comes to get married." Discontented with North Korea's film industry, he defected to Seoul in 2004.

Kwak, who spent eight years serving in the military as a security guard for the late North Korean leader Kim Il Sung and the Kim family, leveraged his knowledge of the North’s General Political Bureau, vacation homes for top politicians and a secret mission team called "Section 11" into the show.

He said that the script writing team had done an enormous amount of research on North Koreans' daily lives. The show's sets were built to resemble a North Korean village.

“The village setting was very North Korea-like. There was a gravestone engraved with sentences paying respect to the dearest Kim Il Sung, which made me feel like I was in North Korea again,” Kim A-ra, an actress originally from North Korea who defected to South Korea 11 years ago as a teenager, told ABC News. “The colorful costumes people wore in the village were very Pyongyang-style. And how people secretly traded products from the South was also what I saw back in the North.”

Meanwhile, the show has also drawn criticism as well for its rosy portrayal of North Korean society. South Korea’s Christian Liberal Party sued the show for violating the national security law and glorifying North Korea. Kwak explained that the show had no political purposes at all.

“There was no need to talk about nuclear weapons, it’s a romantic comedy,” he said. “The show refrained from touching upon the supremacy, human rights issues and nuclear issues because there was no need to.” Kwak said he hoped to direct his own film one day, perhaps about what happened to the American student Otto Warmbier while he was in North Korea.

Former North Korean diplomat Thae Yong-Ho, who defected to South Korea in 2016 said he watched the entire series with much interest and pointed out that the show will surely make its way to North Korea through black markets. "Aside from the issues of content, one thing for sure is that this drama will be very much popular," he wrote in a Chosun Ilbo newspaper column.