Modern † Romanesco

The school has had so many mysterious incidents occur on campus that it's earned the nickname "Ghost Academy." Nanako Manzeiin, a young lady who returned from overseas to inherit the school, and Ryuichi Yajigami, a demon hunter with quadruple personalities, team up and put their lives on the line to exterminate all kinds of evil spirits! Non-stop horror action!

(Source: Comic Alive, translated)

Note: Chapter count includes one omake chapter.