SEOUL (The Korea Herald/Asia News Network) - It's a challenge trying to find a crack in the pristine public image of actor Song Joong Ki, who has been enjoying the most explosive pan-Asian popularity since last year's hit drama series Descendants Of The Sun.

In his numerous interviews, he has been modest yet firm in his opinions and his self-descriptions are humble.And he has taken on another dashing, heroic role in Ryoo Seung Wan's war film The Battleship Island, which hit theatres in South Korea on Wednesday. The movie opens in Singapore on Aug 17 and the actor will be in Singapore on Aug 8 to promote it.

The 31-year-old actor is at the centre of another media whirlwind - his upcoming October marriage to actress Song Hye Kyo, who co-starred in Descendants.

"I never wanted to get married late," Song says on what the public perceived as a sudden announcement early this month, at an interview with The Korea Herald in Palpan-dong, Seoul on Tuesday.

The actor had nothing but praise for his intended, saying he had learned from her professionally during the Descendants shoot and later as a person during their off-screen relationship.

"She's a very thoughtful person," he says, also describing the veteran actress as his senior when it comes to Hallyu fame.

"Every part of our lives is being talked about. I'm only human and there are times when I have my concerns. But I think we can deal with (the media) wisely."

The two are in the midst of "happily preparing" for their wedding, he says. "Nothing is for certain of course, but I'll probably be thinking about my next project after the wedding. Nothing is in the works right now."

His role in The Battleship Island is Park Moo Young, an elite soldier of the Korean Liberation Army and an agent with the United States Office of Strategic Services.

In the film, Park infiltrates Japan's Hashima Island, where hundreds of Koreans have been taken captive and are forced into slave labour in coal mines, to rescue a key independence movement figure.

The character is propelled by a sense of compassion for the downtrodden, Song says.

"At first, he's a soldier whose duty is to follow orders and complete his mission, and that's it. But he's later moved by the plight of the people on the island. His motivation changes as the movie progresses. He later feels he has a duty to save the Korean people."

The strong sense of responsibility could be a trait Song shares with the character. As an actor whose following has expanded overseas, taking on the sensitive subject of Korean-Japanese history could have presented a dilemma. "People ask me if I was concerned about foreign fans' responses before deciding to do this movie. Of course I pay attention to fans' responses. I've reached a point in my career where one photo of me is uploaded on the Internet and all of Asia sees it.

"But I believed that (what the film shows) was just. It's the right thing to do, which is why I think I wasn't afraid. It was a small expression of my beliefs."

The history of Japanese oppression of the Korean people is still worthy of righteous anger, he stresses.

"If you're someone with common sense, it's only fitting that you're angered by these events."

On a day-to-day basis, he describes himself as a social creature who is happy to engage in group activities. "I think that's why I was able to adjust so well to life in the military," he says.

His school years also point to a sociable personality. He was student council vice president in high school and an active member of an association of university students' broadcasting systems while majoring in business administration at Sungkyunkwan University.

Song says the thoughts and opinions of his contemporaries are important to him.

"I go to the theatres a lot to see the movies I'm in," he reveals. "Sometimes, I am sitting right next to someone, so close that I can hear their breathing. It's fun to see that I'm on the screen and they don't know I'm right next to them."

He takes note of the points in a film which evoke the collective sighs, gasps and laughter from the audience. "After the movie, when people go out talking among themselves, I can hear everything. Sometimes even the bad things."