Maou Reijou kara Hajimaru Sangokushi: Touhakuden

Sasane Shirokawa (30) is a former trading company employee and a huge fan of Romance of the Three Kingdoms. One day, after losing consciousness in Chinatown, he wakes up to find himself in the form of a little girl. However, the new body he finds himself in isn't just any little girl, but the daughter of the infamous tyrannical Dong Zhuo, Dong Bai. In order to avoid the fate of being executed alongside Dong Zhuo, Dong Bai will have to use both experience as a Japanese businessman as well as knowledge of the era!

(Source: Square Enix, translated)