I Made One Mistake! Now I Have To Become the Demon Lord in Another World, But I’m Just a Frail Vampire Girl?!

Toshihide Yukawa is a Japanese scientist working in Switzerland, who during a late-night particle-physics experiment sets off a chain reaction which kills him andclaims the lives of millions. Now a mysterious girl offers him an escape from divine retribution. Become a Demon Lord in another world or be removed from existence.