Bloodhound: The Vampire Gigolo

Kranken Haus, an ornate entertainment club for women, is filled with handsome men costumed as vampires who serve as bartenders and escorts for females desiring company and attention. She confronts Suou, a gorgeous man working at the club as a host, whose name is on the card. He denies any involvement with her disappearance and tries to brush her off. Rion concocts an incident and starts working there too so she can keep an eye on him and the club owner. (amazon.com)