I was a stay-at-home kid who was suddenly reincarnated into another world and became a prince of a country, but... I was going to be killed on the first day of my birth. Just when I was abandoned in the forest, I encountered a huge monster... The new life of the monster girl and her step-sister, hugging each other on both sides, begins! Adapted from the light novel of the same name by Cheng Mingcai.