A girl reincarnated into another world as a vampire's familiar bat evolves into a vampire after drinking the blood of a dying man.This causes her to evolve even further, achieving the incredible feat of evolving into a high-ranking vampire.The bat's life as a humble bat suddenly changed, and she was given the name Merril and given the status of a vampire princess.Then, Merril's father, the vampire, declared,"Merril, rule your own territory as a vampire!""No way!"Merril had a weak mentality and was intimidated by monsters, but as soon as she realized the incredible strength she had gained by evolving into a high-ranking vampire, she changed her mind and set out to claim the territory."All right! Let's go and claim the biggest territory in the world!"　This is the story of a reincarnated girl's rise from a weak bat to become feared and known as the Pure White Vampire Princess!This work is also serialized on Kakuyomu.