Two stills of Siwan in his role as Minjae in  "One Line" was released recently.  Siwan apparently took on a character that he has never actually done before. The movie will reportedly start playing in theaters at the end of March.

Siwan, according to Allkpop, plays the role of a college student who looks innocent and pure in the movie. He gets recruited by a group of con men and eventually turned into one of the best among them. 

Reportedly, Siwan's character role is someone who looks upright with an innocent face.  Apparently, somebody who looks like he is not going to be involved in any fraud at all. However, the emphasis of his character is that he has the talent of manipulating people's desires.

"One Line" is, accordingly a movie about a group of fraud artists who run a large-scale insurance scam, starring Siwan and Wang Ji-won.  Wang takes on the role of Hae-seon, a beautiful and smart woman who is Siwan's partner and friend from school. In real life, both reportedly are of the same age.

According to Wikepedia, Siwan is a singer, actor and television host. He is a member of the South Korean boyband ZE:A and its sub-group ZE:A Five. As an actor, he also starred the film "The Attorney," and the cable series "Misaeng." Both were successful in the box office and ratings.

Siwan, reportedly won Best New Actor at the Max Movie Awards and the Marie Claire Film Festival. He also received acting nominations from several acclaimed awards giving organizations.

In Jan. 2016, Siwan accordingly starred alongside Go Ah-sung in the war drama film "A Melody to Remember." He was also a member of the cast in the prison film "Hooligan," and in the Chinese-South Korean web drama, "My Catman" alongside Chae Soo-bin and L of the Infinite band.