Senjo Yona, a girl who was severely bullied and eventually killed in a gas explosion. After her death, she is reborn as『Lean Bloodlord』, the daughter of a vampire chieftain, through the power of the evil god Isuzu. There, a peaceful and harmonious life awaits her that is incomparable to her previous life. Surrounded by her loving parents, she made friends and lived a life of smooth sailing. ――But that time suddenly comes to an end because of humans who, for unreasonable reasons, want to eradicate the vampire race. 「Ah, I see. My life is ruined because there are humans.」 On the other hand, there is a girl who has been treated as a nuisance in a certain village. She has the qualities of a『Hero』and has tremendous talent and potential for the future, but her mind has been broken by humans, she has been brainwashed, and she is being used as a living weapon. 「In truth… I don’t want to protect people. I don’t want to be a hero.」 Eventually, they met, two people with an intense hatred for humans. And they become a disaster for humans. This is the story of two girls whose lives were ruined by humans and who once lost everything but their lives, and how they now use every means at their disposal to destroy humans and take revenge.