Bianca Edelweiss is well-known as an evil weapon specialist. She dies from experimenting her last weapon masterpiece. She's sent to the underworld facing the king of underworld. She's judged to reincarnate as a wild beast. But the tables have turned when discovered that she had good deeds. Because of this she is given the opportunity to become a good person. She's reincarnated in an another world where she was given a mission to save the world and put an end to the Nightmare Emperor with its Eight Deadly Sins. But how can she accomplish this mission? Especially since she reincarnated as a baby?! Follow the story and the adventure of a cruel and ridiculously cute baby!