"It takes courage to do what others don't. You get 'Ggang' only when you're desperate," said Yu Ah In, a main character of the movie, "Tough As Iron"

People call him Ggang Cheol in the movie, although his real name is Kang Cheol. He is diligent, working in the loading dock of Busan's many ports, but the world, like a bully, doesn't leave him alone. While his mother (Kim Hae Suk) suffers sick bed, his boss suggests a dangerous work opportunity for him. He puts desperate Kang Chul into danger saying, "You get 'Ggang' only when you're desperate."

Yoo Ah In, who became the most representative 20 something actor after his performance in "Wan Duk I," which have gathered five million people, came back to movie screen as Kang Cheol in "Tough As Iron" in two years. He told the news that when he first took a glance at the title, he thought it would be similar to 'Wan Deuk I' and didn't even read the scenario. But when he delved into it, he got a good feeling about 'Tough As Iron,' which is why he picked this as his next movie.