Chan Dou Ba, A Bu!

Based on a novel by Feng Diu Zi, an alien crash lands onto earth and possesses the body of Tang Qing Ye, igniting a sweet and funny romance with her 'brother' Tang Qing Feng. During the reign of Dai Zong, there was continuous unrest across the borders. The 6th Prince Li Yi was named as the Crown Prince after he succeeded in defeating their enemies. He also made plans to marry his childhood sweetheart Tang Qing Ye who is the illegitimate daughter of the Tang Family. Tang Qing Ye's stepmother finds out about it and sends assassins to kill Qing Ye while using her political pull to ensure that her own daughter is married to the Crown Prince instead. As Qing Ye runs for her life, Ah Bu Cha Cha's spaceship crashes on earth, and she is forced to inhabit the body of Qing Ye, pretending to be Tang Qing Feng's little sister in the process. Tang Qing Feng and the Crown Prince are two outstanding young leaders of their time. Together with Qing Ye, the three become embroiled in a dangerous conspiracy. Meanwhile, there's also the part about aliens in this story.