Set during the Qing Dynasty of China in the mid 18th century, Man in Charge tells the story of an official adviser, Chau Bing (Kenneth Ma), and his relationship with the young county official, Shum Kwan-Pok (Matthew Ko). Bing obtains a secure job as Kwan-Pok's private adviser and the two become good friends. They both try to root out Manchu government corruptions.
Chau Bing was brought up by his mentor, who teaches him how to be an adviser, as he was an orphan that his parents died when he was young. Chau Bing's parents had plans to kill the emperor Yong Zheng but failed to do so as it was found out and was killed. In order to investigate the case, Yong Zheng set up a group. One of the spy is Chau Bing's wife Chiu Yok Hing. Chiu Yok Hing is good in Kung Fu and was given the mission to marry Chau Bing to find out who was the master mind of the whole plan. However, no news could be found out of Chau Bing as he did not know anything about it. Chiu Yok Hing was told to kill Chau Bing to close up the case as the group was to be dismissed but she did not as she gradually fell in love with Chau Bing.
However, Shum Kwan-Pok totally changed to a villain, he in directly made his biological father commit suicide in the prison, and tries to kill Chau Bing to keep his secret as Chau Bing got to know that his mentor Dai Lou See is actually Shum Kwan-Pok's biological father but gave him away to Shum Lou Ye as that time there was a scholar who wrote something which offended the king, Yong Zheng, and was killed, and since then the tests for scholars in order to be a county official is diminished. Dai Lou See wants to see his son being a county official, so he gave his son to Shum Lou Ye.
Chiu Yok Hing was killed while saving Chau Ping when Shum Kwan Pok hired assassin to kill him.