The new tvN drama "The K2" got a lot of positive comments after airing its first episodes. Producing director (PD) Kwak Jung Hiwan revealed how hardworking the two leading stars are.

After the first episode of the drama, many had left comments about the impressive action skills of Ji Chang Wook and YoonA's moving performance. "Ji and YoonA are actors that will become even better in the future. There is a lot of potential for development," Soompi quoted PD Kwak as saying during a conversation with news outlet TV Report.

Kwak added that the two are putting a lot effort to give viewers a fervent performance. Stressing that the two may get a lot of praise for their acting in this drama.

YoonA even got bruises on her knees from the scene where she was picking up coins in the street. The lead stars are really dedicated to their work and do not care of the possibility that they might get hurt.

Performances of Soong Yoon Ah and Jo Sung Ha even shocked Kwak, stressing that Jo had lost eight kilograms prior to filming for his role. However, Kwak is worried because "The K2" are not just compared to any other dramas but also to "Bond" films.

But Kwak promises that they will continue to do their best even if there are always regrets along the way. The producing director also thank all the viewers for their interest on the show and asks that they keep supporting it.

Meanwhile, on Sept. 23, Ji posted a photo in Instagram with a caption, "Hello. Please give lots of love to our drama 'The K2'," AllKpop reported. In the photo, Ji and YoonA pull a serious looking face with moles drawn onto their faces.

"The K2" premiered on Sept. 23 at 8:00 p.m KST on tvN. In the drama, Ji plays as a bodyguard to YoonA, who is a secret daughter of a presidential candidate.

Catch Ji and YoonA in "The K2" below: