In this world, monsters are humanity’s mortal enemies. Said to have been created by an evil god, monsters are monstrous beings whose only instinct is to kill humans. Since I was reincarnated as such a monster, I decided to live a peaceful life, avoiding being found by humans. With that resolve, I have lived quietly until now. But one day, I found a person collapsed near my home. What’s more, the person lying there was the heroine I had been rooting for in my previous life. She was extremely exhausted, and I decided that her life would be in danger if she continued like this, so I couldn’t just abandon her and decided to take her under my protection. This is the story of the protagonist, who has been reincarnated as a monster, overcoming difficulties together with the original characters.