Set in Yokohama, this is the story of a priest with a "survival wish" and a vampire with a "death wish".

After hundreds of years, Mary - an immortal vampire with a death wish - finally finds out the whereabouts of Maria - the exorcist who possesses the "Blood of Maria" that can exterminate him. But, it turns out the Maria he found is not the right "Maria"! However, as Maria does inherit the "Blood of Maria", he is constantly being targeted by vampires, so constantly that he hardly has time to catch his breath... And so, Mary makes a proposal to Maria: if Maria pledges to kill him, he will protect Maria from the vampires until the threat is gone, and... The story begins!

[Summary from MEGU-Scans]