The Haunted Bookstore - Gateway to a Parallel Universe Novel Volume 4 was written by Shinobumaru with illustrations by Munashichi.

Something wicked this way comes—and it isn’t a spirit. A strange fox-masked man has breached the boundaries of the spirit realm, and his designs are as life-threatening as they are mysterious.

Worst of all, Suimei suspects that the man is an exorcist, so as a safety precaution, he asks Kaori to move in with him. Neither Suimei nor Kaori expect the spirits to kick up such a fuss over his simple suggestion, but it’s plain as day to everyone else that the two are more than friends. Will they understand their feelings for each other before this new threat tears them apart forever?