Sub Maid & Secret Guard

Quick answer: 9 episodes, English original audio, and episodes 1–9 play right here tonight.

In order to cure her mother's illness and earn money for medicine, Chu Wanqing took the risk of being beheaded and went to study in the academy instead of the profligate Xu Wenjin. There, she met Fu Jingxiu, a royal guard who secretly came to the academy to look for the border defense map. To escape from being hunted down, Fu Jingxiu hid in Chu Wanqing's dormitory. He threatened Chu Wanqing to help him drive away the officers and soldiers. After escaping, he found that the border defense map was lost in Chu Wanqing's dormitory.

In order to find the map, he became Chu Wanqing's roommate. During their daily interactions, he was gradually attracted to Chu Wanqing. However, due to Chu Wanqing's appearance as a man, he always refused to reveal his true identity. But later, when he saw Chu Wanqing wearing women's clothes and realized that she was a woman, he seized the opportunity to pursue her and tried every means to protect her. Finally, he won her heart.