Zuo Shuang Tao --- Guan Xiao Tong
Nationalist Party Military Intelligence Agent,Codename: 'Red Heart Five'. A charming and daring intelligence agent with a quick wit.
Chen Jia Ping --- Han Dong Jun
Chinese Communist Party Underground Party Member, codenamed 'Plum Blossom Four' A Chinese Communist Party agent with 'dual identities,' appearing as a carefree and unruly individual on the surface, but internally a steadfast revolutionary youth.
Zhao An --- Tian Lei
Vice Chief of the Intelligence Station, Deputy Head of the Action Team of the Japanese Garrison's Shanghai Command, and the second-in-command of the Taihe Chamber of Commerce. He has a tendency to overshadow Manager Luo Guanqun and has emotional entanglements with Mrs. Luo. He regards Japanese people as his superiors. From the moment he arrested the suspect at the station, he suspected the true identities of Chen Jiaping and Zuo Shuang Tao. In the interrogation room, he used every method possible, except for using physical torture, to meticulously interrogate them. Later, he secretly arranged personnel to monitor the two main characters for an extended period.
Han Lu --- Lu Zi Zhen
Hanlu is a well-known film actress. Chen Jiaping has also watched the movies she starred in. Initially, Hanlu was mistaken for a collaborator and was assassinated at the station, but she was saved by Chen Jiaping, and they became close friends. She was the first love of Jiang Zhaoguo, the Minister of Foreign Affairs of the Kuomintang, and their relationship is very complicated. Later, she met Yamashita Takeo and developed feelings for him. Due to the helplessness and irresponsibility of Jiang Zhaoguo's mission, she dedicated herself to Yamashita. Her wedding with Yamashita plays an important role in this drama.
Luo Guan Qun --- Jiang Yi
He is the top leader of the Taihe Trading Company. Initially, Chen Jiaping was supposed to carry out a tracking mission, but due to a twist of fate, he ended up saving his life, which allowed him to infiltrate the company. He was not only deceived by his wife but also manipulated by his subordinates, making him a hollow man. However, he is very cunning, understanding the art of concealment and acting slyly. He is not genuinely devoted to serving the Japanese but rather seeks money and status. He has an interest in calligraphy and painting. He fell from grace due to a deal with Yamashita that was betrayed by his wife, and ultimately met his demise in the pursuit of wealth.
Lu Fang Fang --- Wang Xiu Zhu
Lu Fang Fang is the administrator of the Confidential Archives Department and also the accountant of the Finance Office. Lu Fang Fang has a strong liking for Chen Jia Ping, so she doesn't show any kindness to Zuo Shuang Tao. Lu Fang Fang's true identity is also an underground party member with the codename "Parrot." In the end, she sacrifices herself to save Chen Jia Ping.
Liu Wu Chang --- Liu Hai Kuan
He is the chief instructor of the Kuomintang Special Agents Training Camp, as well as the captain of the Suzhou-Zhejiang-Shanghai Action Team. He is capable of personally engaging in combat and achieving victory from thousands of miles away. He came to Shanghai due to the Kuomintang's assassination mission against Yamashita Takeo, and he is a top-level agent among the special agents. The agents trained under him are all elites among elites. He has strict demands on his subordinates but is also protective of them, and he greatly admires Zuo Shuang Tao. However, he gradually becomes attracted to the communist ideology. After Jiang, the Minister, discovers this, he kills him and frames Chen Jia Ping for the crime.