Koukyuu no Hanayuishi

Shao Mei is the lowest ranking court lady in the imperial harem. Though her job is to pull weeds, she possesses one special talent - the skilled touch of arranging the flowers that adorn woman's head, their symbol of dignity and their life. Despite her dreams of becoming an official florist, her low-ranking status bars her from taking the exam. One day, however, the emperor's wife comes to seek Shao Mei's aid. Shao Mei's arranging technique and floral abilities become the keys to saving the case swirling around the palace.

(Source: Square Enix, translated)