In his numerous interviews, Song has been modest yet firm-footed in his opinions. His self-descriptions are humble and his assertions rooted in a belief in justice. It doesn't help that Song has taken on another dashing, heroic role in Ryoo Seung-wan's war film "The Battleship Island," which hit theaters Wednesday.
The 31-year-old actor is at the center 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 said 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 moments in their relationship.
"She's a very thoughtful person," he said, 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, Song said. "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 most recent role is Park Moo-young, an elite soldier of the Korean Liberation Army and an agent with the US 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 labor in coal mines, to rescue a key independence movement figure.
The character is propelled by a sense of compassion for the downtrodden, Song said.
"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; but Song cited the socially accepted notions of "common sense" in his decision to speak out against the historical contentions surrounding Hashima Island.
"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, Song stressed.
"If you're someone with common sense, it's only fitting that you're angered by these events."