Actor Kim Seo-hyung explores why bad things happen to nice people in the thriller "Greenhouse," in which she stars as the protagonist.

The story of “Greenhouse” revolves around a nurse and caregiver, Moon-jung, who lives in a greenhouse. It delves into the character's downfall as she tries to cover up the accidental death of an old couple in her care.

Kim said she cried after reading the movie's script for the first time.

“I did not ask myself whether or not I could do this project. Instead, I chose to focus on portraying the reasons why these kinds of (difficult) things only seem to happen to nice people,” Kim told reporters during a press conference held at Lotte Cinema's Konkuk University branch in Seoul on Tuesday.

“The characters in the film are the kind of people that I felt sorry for, the people I hear about on the news. They’re the kind of people that I would not want to meet in real life (as they get themselves involved in unfortunate accidents),” Kim said.

Kim recently played an unfortunate character in the TV drama “Pale Moon,” who struggles with an abusive husband.

When asked whether playing a character plagued by misfortune was tiring, Kim noted that she normally immerses easily into her roles.

“I wondered why I have to meet such sad characters in my acting. So I asked the director about her intentions (behind the role) and then decided to star in the film,” Kim said.

Director Lee Sol-hee said she didn’t mean to “hurt” Kim by casting her in the role.

“Kim and I had a lot of conversations while shooting this project. I saw her talking to birds and cats for an hour at the shooting location and such aspects were very close to the character she was playing," Lee recalled. Despite her concerns that Kim's assimilation with the character might cause some torment for the actor, Lee said, "The result is that she showed multi-dimensional acting, so I am happy with (the outcome)."

“Greenhouse” hits local theaters on July 26.