In the 1940s, the capital of Korea was under the rule of Japanese imperialism. It was a time of chaos and confusion. In order to survive, people could change their own names, not to mention the names of their nations. The Japanese military stationed there tried their best to obtain the super diamond "Millennium Light" worth 100 billion won (820 million RMB) between the eyebrows of the Buddha statue of Seokguram Grotto, which was known as the symbol of the millennium of Silla history. After years of hard work, the director, as the supreme leader, finally got it, but suddenly found an ominous sign of the emperor's demise on the diamond, so he ordered the diamond to be transferred to Japan. Prior to this, Lieutenant Yamada (Kim Soo-hyun) was responsible for holding a farewell party. One night in May 1945, at the farewell party, the "Millennium Light" that was regarded as a treasure by the Japanese was stolen by an unknown female thief. The whole city was in an uproar. In order to retrieve the giant diamond, the Japanese army killed many innocent civilians. Everyone "changed color when talking about diamonds". …Outside the gorgeous bar, there is a notice offering a reward for the masked thief “Begonia”. Inside, there is singing and dancing. The jazz singer Chunzi (played by Lee Bo-young) attracts the men present with her equally charming voice and figure. And it is precisely “Begonia” who can still take diamonds under the strict defense! Every night, the gentleman man Jin Fengjiu (played by Park Yong-woo) who must come to sing the last song is a gentleman who is addicted to the world of flowers and flowers on the surface, but in fact, he is the most cunning antiquity fraudster with thousands of masks. Fengjiu who is tracking down the traces of Begonia, the Japanese army who is biting on Begonia, Yamada who is gradually suspicious of the identities of Chunzi and Fengjiu, and other diamond-rejecting people with their own ulterior motives, staged a thrilling war of ambition!