How different can three brothers be? Viewers will find out this spring when the MBC drama "Triangle" tells the story of three brothers who were born in a wealthy family but were then tragically separated while they were very young.

One of the brothers grows up to become a gangster. Another becomes a police officer and the third remains with their wealthy parents, growing up with all the luxuries and opportunities that his siblings were denied. Will nature matter more than nurture? Will the child who grew up in the most comfortable circumstances be a better person? The drama will play with these notions and let the viewers decide.

So far, Song Seung Hoon has signed on to play the role of the gangster brother. It won't be hard to get in character as a thug. In 2013 Song Seung Hoon played a gangster in love in the melodrama "When A Man Loves."

Lee Beom Soo, currently playing the Prime Minister in "The Prime Minister and I" will play his police officer brother.

Z:EA's Im Si Wan, who was recently seen in the romantic comedy "Expecting Romance" and appears in the 2013 film "The Attorney," will play the brother who remained behind. Although Im Si Wan is best known as a k-pop idol, he has appeared in more than a half-dozen dramas.

It will be a reunion for actors Song Seung Hoon and Lee Beom Soo who worked together on the drama "Dr. Jin." But given that they are now on opposing sides of the law, it is likely that there will be some conflict between the characters.

Also considering a role in this drama is actress Lee Mi Yeon, who recently appeared in the variety show "Noonas Over Flowers." Word is that Lee Mi Yeon's character will be in a tragic relationship with Lee Beom Soo. It's Lee Mi Yeon's first drama role in four years since she played Kim Man Deok in "Merchant Man Kim Man Deok." She appeared in the 2012 film "A Company Man."

Another actress considering a role in this drama is Go Ara. Her popularity rose dramatically in 2013 because of her role in the nostalgic hit "Reply 1994." In "Triangle" the actress will romance Im Si Wan.

Yoo Chul Yong, who worked on "All In," 'Swallow the Sun" and "Poseiden" will direct the drama. Writer Choi Wan Kyu worked on "Midas," "Iris" and "Swallow the Sun." "Triangle" is scheduled to follow "Empress Ki" in April.