My Dear, Curse-Casting Vampiress, Vol. 3 (manga)
After a grisly murder takes place at a local high school, the victim is found to have had contact with a vampire pretending to be Baroque. With the school blocking attempts to investigate, Isuzu and Baroque go undercover as teacher and student to infiltrate the school…but they didn’t anticipate the fake Baroque showing as much interest in Isuzu as the real one! Caught in a tug-of-war between two vampires, can Isuzu maintain his cover story and catch the murderer?!