The setting is a fictional modern Western nation.

In this world, beings that are not human, starting with vampires, certainly exist. However, their presence is hardly known to general society, and most are now confined within old legends and superstitions.

──A large, old mansion standing slightly apart from human settlements. A single vampire—Clive Vells—lives there.

He is a vampire who has survived for a long time—roughly eight hundred years—and his abilities are genuine. He is certainly not a weak existence... or so it should be. ...However, there is one very large problem.

Almost every weakness of vampires told in folklore works on him.

Sunlight is, of course, out of the question. Garlic is no good either. He can't even enter a person's room without being invited. Normally, a great vampire would have overcome one or two of those outdated weaknesses, but they apply to Clive with surprising faithfulness.

A vampire so traditionally riddled with weaknesses is rare these days.

──And Guest is his sole caretaker.

Closing all the curtains in the mansion, paying attention to meals, avoiding trouble when going out, and every day, even grooming the master who doesn't reflect in mirrors. He is arrogant and his pride is second to none. But if left alone, he'll get caught up in one vampiric weakness or another.

This is a story depicting the daily life of such a slightly—no, quite—handful vampire and Guest, who stays by his side.