Kyuuketsu Senki Vjedogonia
吸血殲鬼ヴェドゴニア
One night the protagonist sees a beautiful woman in distress; he tries to help her but she bites him. She turns out to be a vampire! And now he will turn into a vampire too, unless he finds her again and destroy her first. He then joins with a group of vampire-hunters.
(Source: VNDB)