One day, the diligent and chaste Sister Erna's church is attacked by vampires. The pleasure from the venom in their fangs overwhelms her body and sets her heart and her mind at odds. Thus rises the curtain on a bewitching vampire romance!!

Official Italian Translation: https://www.animeemanga.it/2019/09/12/sister-vampire/

Kayano's first love, the prince-like Moriya, moved away to France when they were children. Years later, he returns, but with a completely different personality. Her only memory of the old him is a flower bookmark...