Koukyuu no Hanayomi Sennyo

Kouken was born with a flower birthmark, which shows that she has a special power to use Kasen Mystics, the flower sorcery. She was able to read the memories of flowers and send the poor souls that still linger in this world as wraiths. However, this sorcery was now hated by the empire. Because Kouken was the only one in the village with the power, she was treated cruelly by everyone. When an envoy from Shuuyou, the imperial capital, came to the village, Kouken was captured and taken with them. The fourth prince, Shuurei, found out that she has the power he was looking for and took her to the inner palace. Kouken starts dealing with wraiths and send them to the pure land, which leads to solving mysterious cases inside the inner palace. (Source: BookWalker)