Dump the Queen

The protagonist, Zhou Fan, transmigrates to the Great Qian Dynasty, becoming the second son of a concubine in the Zhou State Duke's mansion in Yunzhou. He is betrothed to the Empress, but Zhou Fan doesn't want to become a male concubine, so he feigns a life of dissipation for three years. However, he secretly researches science and quietly strengthens his power. Three years later, the Empress can no longer tolerate him and issues an edict to annul the engagement. The Zhou State Duke angrily denounces Zhou Fan as a son of a lowly concubine and banishes him from the Zhou family. The Zhou State Duke then goes to see the Prince, who announces plans to assassinate the Empress. Zhou Fan leaves with his maid, Xiao Chun, and goes to the Tianxiang Pavilion to see the courtesan, Xi Yue. Unbeknownst to him, the Empress has also come to Yunzhou to see what kind of person Zhou Fan is. Seeing him enter the brothel, she is angered and disguises herself as a man to follow him.