"Bloody" Mary, a vampire with a death wish, has spent the past 400 years chasing down a modern-day exorcist named Maria who is thought to have inherited "The Blood of Maria" and is the only one who can kill Mary. To Mary's dismay, Maria doesn't know how to kill vampires. Desperate to die, Mary agrees to become Maria's bodyguard until Maria can find a way to kill him.
Another “Mary” who resides within Mary turns out to be the one who killed Maria’s father, Yusei. In search of why his father had to die, Maria tries to get in contact with “Mary” but is unsuccessful. In the meantime, a mysterious man pays a visit to Maria and reveals how Maria’s mother first met Yusei and provides crucial information about Maria’s family lineage.