Vampires are known to have various vulnerabilities that balance out their immense power, but Draluc, the vampire ruler, is vulnerable to almost everything. Ronald, a vampire hunter, is sent to penetrate the castle of the so-called "Invincible Progenitor" and save a woman's son from the monster within. When he arrives, however, he is astounded to see that the vampire is instantly turned to ash by anything as insignificant as a clap of his hands! Furthermore, the boy he was assigned to save had just walked in to play video games with the vampire ruler while he slept! Draluc's castle is destroyed in an unfortunate turn of circumstances, and the frail vampire chose to live with the hunter who has just recently vanquished him.