Kunisaki Seika Equites

The dark-skinned heroine of this work, who attends Santo Academy.

She is a young lady from a good family who lives in a large mansion with maids and butlers.

Kunisaki has the blood of an excellent exorcist (demon exorcist) in her veins, so much so that an Indian aristocrat was once bought by the British royal family and welcomed into the aristocracy. The family has a long line of demon exorcisers who have exorcised demons in Japan for generations. Seika is the most powerful of her family. She used her powers to leave Japan and become an exorcist based in England. She uses the Misericorde dagger, a sword blessed by the cathedral, as her weapon.

She is older than Ryusuke and is a returnee.

She was born in Japan, but spent a long time as an aristocrat there, so she is quite selfish, arrogant, and proud. She behaves condescendingly, especially towards Ryusuke, because they are in a master-servant relationship. She doesn't mind her servants seeing her skin, and often makes Ryusuke help her get changed and take a bath.
Her good looks make her popular with the boys at school. Many people like being treated harshly by beautiful women, and as the granddaughter of the Yamato Academy's owner, she is nicknamed Seika-sama.
Although she would normally choose a partner when she gets her first period, known as the Fertilizer who will replenish her spiritual power, she has yet to decide on one, and it seems her grandfather, the head of the family, is trying to decide for her without her permission.
She does not like the master-servant relationship between Ryusuke and Umihime, and has been growing increasingly irritated since Umihime appeared.