Kusuriya no Hitorigoto

There is a certain large country in the central plains of the mainland. In the imperial court of its emperor, there is a girl. Her name is Maomao, a pharmacist from the pleasure district, who is currently working as a maidservant in the inner palace. The girl, who surely can not be considered a beauty, is keeping a low-profile waiting for her contract to end. She is confident that she will not be “visited” by the emperor. During that, she learns about the short lives of the children of the emperor. Maomao, hearing that the two surviving children are critically ill, begins her investigation for the cause—. Set in the middle ages of the East, the “Food Taster” girl continues to solve difficult cases in the imperial court one after another. — Description from novelcodex.org