It's hard to imagine the star of "Empress Ki" as being shy. Ha Ji Won in the role of Seungnyang toppled the heads of the Yuan Empire and survived several poisonous palace scourges.

Yet, her co-star Ji Chang Wook says that the actress is actually quite shy and made uncomfortable by strangers.

"I am afraid of strangers but it seemed like she was too," the actor recently told TV Daily.

Both actors may have been shy with strangers but they were comfortable working with the saeguk's cast and crew. And they quickly grew comfortable with each other.

"Thankfully the first few scenes of the drama were of Ta Hwan and Seungnyang playing around with each other so naturally we got close," he said.

In the drama, Seunyang pretended to be a boy and she protected the prince in exile. Her character showed his how to shoot an arrow and they rode together on the beach.

Not only did their characters grow close but the two also got to know each other well during the filming of the 50-episode historical drama.

At one point he said that he spent so much time with Ha Ji Won that it felt as if he was her manager. He said he helped her but never said exactly how. Perhaps he helped her avoid the strangers she wanted to escape.

"Sometimes it's scary how I've become used to helping her," he said.

Altogether he really enjoyed working with her.

"She's a really good listener and she gave me a lot of advice," he said. "She gave me suggestions on how to do things differently. She's very responsive too. She laughs a lot so the filming site was always cheerful.

Earlier this year he was asked to choose his ideal type from among Empress Ki's three female stars. He opted for Ha Ji Won rather than Baek Jin Hee, who played the evil Empress Tana Shiri or Kim Seo Hyung who played the Empress Dowager. He even sent a note to Baek Jin Hee asking her to be kinder to Ha Ji Won.

At the time he justified his choice by saying that Ha Ji Won was bright, optimistic and healthy.

"She's fit and healthy, so I don't think she gets sick easily."

Together the actors created one of the year's best k-drama couples but they've both moved on to other projects.

Shortly after filming the last episode "Empress Ki" he shot a musical mini drama titled "Caffeine," for his fan meetings in Japan, which will run through June 7. His next project is probably the film "Two Constables."

Ha Ji Won will next be seen in the film "Blood Merchants," which is based on a Chinese novel.