The much-anticipated drama "You're Surrounded" has started filming. The SBS drama focuses on four rookie detectives in the violent crime unit of Seoul's Gangnam Police Precinct. The upscale address means their clients will number among Seoul's rich and powerful.

Three actors with recent hit dramas have been cast to play young detectives. It will star Lee Seung Gi, last seen in "Gu Family Book." He plays rookie Eun Dae Goo, a smart guy who pretends to be tough but has secrets that make him vulnerable. Go Ah Ra, who had a role in "Reply 1994," plays upbeat rookie detective Eo Soo Seon. She is the only woman in the unit but that does not mean she is easily intimidated. Ahn Jae Hyun, who had his first drama role as Jun Ji Hyun's kid brother in the hit "You Who Came From the Stars," will play another one of the rookies.

Keeping these rookies in line will be Cha Seung Won, who appeared in the Hong Sisters' comedy "The Greatest Love." He plays Seo Pan Suk, the leader of the violent crimes unit.

Cha Seung Won's character may prove to be a tough taskmaster on the show. And the characters may worry about measuring up. But on the first day of filming all the actors were very supportive of each other. It felt as if they were part of a family.

Lee Seung Gi said he was nervous when he arrived on set but his worries soon evaporated.

"The set felt as comfortable as ever when the camera started rolling and everyone around me was so supportive," he said. "I think the set is really going to be fun."

Cha Seung Won also commented on the supportive atmosphere that was immediate from the start of filming.

"It felt like a fun day at home where cousins and nephews gather together with their uncles," he said.

Go Ah Ra said that things went so smoothly on the first day of filming that she was eager to return the next day.

The story will include some romance, which will probably involve Lee Seung Gi and Go Ah Ra. Ji Woo plays the younger Go Ah Ra and also played the younger version of Ok Ryeon in the KBS drama "Inspiring Generation." The story of "You're Surrounded" starts ten years in the past with the teen versions of some of the characters.

"You're Surrounded" will air end of April after the completion of "Three Days."