A man collaborates with his oppressors until he realizes collaboration costs everything. He becomes Gaksital, the masked avenger, driven not by ideology but by the breaking point where survival and betrayal become the same thing. The show's real tension isn't hero versus villain, it's watching someone dismantle the person he was forced to become. Japanese colonialism in Korea isn't backdrop here, it's the machinery that grinds individual choice into dust, then demands you choose anyway. By the end, the mask isn't a costume; it's the only face he has left.

A masked vigilante in a Korean bridal mask roams Korea under Japanese rule, punishing injustice. People call him Gaksital, and rumors of him spread among the Korean people. Lee Kang-To, meanwhile, serves as an officer in the Japanese police and seems to have turned his back on his own heritage. His brother Kang-San, a devoted patriot, was beaten so badly by the police that his mind never recovered. To look after him and the others he loves, Kang-To needs money and power, and capturing Gaksital is his route to Japanese favor and promotion. The two men hold opposing views of justice: Kang-To thinks the strong have earned the right to dominate the weak, while Gaksital stands for equality among all people. Their pursuit becomes a tragic drama of patriotism, betrayal and redemption.