Ayakashi Koukyuu no Keiyakuhi: Mofumofu-tachi wo Kanri suru Kantan na Oshigoto desu

Yuri became a palace servant girl to earn money for her adoptive father's medicine, but then she was hired by the handsome Crown Prince Genyao as his “consort” because of her spiritual power! Her job is to watch over the palace to make sure that no one misbehaves in the Northern Palace, which is full of dangers. "Ayakashi may be cunning 'creatures,' but they are not evil!" Yurei tries to convince him somehow. But one day, someone tries to assassinate Genyao! The story of a contract consort's struggle in the palace harem!

(Source: Kadokawa, translated)