Guys, I wanted to change the title, but apparently you can't do that after seven days. This book is a lost cause, so please check out My Fantasia with the World After Being Turned by the Vampire Queen instead.
The protagonist's true identity is a little vampire princess.
This is a world where magitech, swords, and magic coexist. A twenty-year-old upstanding young man from Earth transmigrates into the body of a knight. He becomes an eighth-rank knight at only twenty, the textbook protagonist setup. But why did I turn into a white-haired, red-eyed vampire girl the night before taking part in the contest for the Holy Sword?! (The protagonist turns into a loli in Chapter 6. I know you like that, but for the sake of the plot, please read the first few chapters.) After leaving the human empire, the protagonist stops hiding her true appearance. While in the human empire, she has to keep herself concealed, since she is a holy knight, but her true self is a vampire. If anyone finds out, it's over.
