Shim Eun-kyung was seen as a promising child actor in Korea for her portrayals of younger versions of characters in hit dramas, such as Lee Ji-ah's character in the MBC series "The Legend" and Ha Ji-won character in "Hwang Jini."

Since then, she has established herself as a versatile actor, starring in films across genres from the coming-of-age film "Sunny" to the comedy hit "Miss Granny" and the crime thriller "Fabricated City." Shim also found success in Japan, becoming the first Korean actor to win Best Supporting Actress at the Japan Academy Film Prize for her lead role in the Japanese suspense flick "The Journalist."

Two decades into her acting career, Shim said that she has recently been grappling with the kind of actor she wants to become.

"I felt like I was an actor lacking any strengths. This led me to a deep introspection and at times, I despaired. I often questioned whether I should continue acting," said Shim during a group interview held on Oct. 21.

Just then, her latest film, "The Killers," illuminated the path forward.

"Director Lee Myung-se places great importance on rehearsals, often encouraging actors to come and read the script whenever they have a chance to practice," she said.

"I realized on this set (for 'The Killers') that only through continuous practice can I improve," she said.

"The Killers," which premiered in local theaters on Wednesday, is an omnibus of four short films, each helmed by a distinct director: Kim Jong-kwan, Roh Deok, Chang Hang-jun and Lee Myung-se. Lee, a veteran director with hits such as "Nowhere to Hide," served as the chief creator of "The Killers."

Each of the four shorts provides a unique take on Hemingway’s classic short story "The Killers," featuring Shim in all of them.

Initially, Shim said she doubted her ability to portray the vastly different roles in "The Killers."

"I questioned whether I could handle this genre and these roles myself. Omnibus films aren't very common these days," she explained.

"However, (this chance) to present a collection of diverse genres to the public became a turning point for me," she continued. "It was an acting experiment, and 'The Killers' confirmed that I could keep creating sustainable films. I believe (participating in 'The Killers') gave me a lot of courage."

Looking ahead, Shim stated her intention to navigate both the Japanese and Korean entertainment industries.

"I have thought about working in foreign countries since I was young. I had ambitious goals. If there were good projects, I wanted to work not just in Korea but anywhere, regardless of nationality (of the film). Japan was one of those places. Fortunately, I signed a contract with a Japanese agency, which allowed me to enter the Japanese market at the perfect time," she shared.

"Moving forward, I plan to maintain a balance between my work in Korea and Japan. If there are promising projects in other countries during that time, I won’t hesitate to pursue those opportunities as well," she added.