Fufufu Darkness

A youkai comedy depicting the activities of the Onimaru Daisuke and Kagekoji clan fighting to protect the world from the dark clan who plans to take over the human world. Daisuke Onimaru, a freshman in college who has no connection with girls, is suddenly attacked by the Poltergeist phenomenon when he sends a female college student, Konoma, who has collapsed due to anemia, to the room. And Daisuke, who consulted with his brother about the matter, was introduced to Kagekoji Shikinemaro ...!?

source: https://www.mangaupdates.com/series/jn899y6/fufufu-no-yami