Fashion King tells the story of a third-rate designer Kang Young-gul who makes and sells counterfeits in Dongdaemun. Previously unable to put his formidable talent to proper use, at a certain special opportunity he becomes a big shot in the fashion industry.
Meanwhile, Lee Ga-young, after losing her parents who had been successful designers in Dongdaemun and even losing their shop, having spent her life in a small room only sewing, tries her utmost to come out of a life of poverty.
Two young people struggle to come out of difficult circumstances and on the other hand, the heir of the country's top fashion industry conglomerate Jung Jae-hyuk won't stop at any means to keep his position.
In the end, what will become of the future of the three who try to succeed as world-class designers?