Rui Ezaki, a company employee, loses his life after being hit by a truck on his way home from work. When he woke up, he found himself in a different world, and in addition, he had become an adorable 3-year-old boy named Elle! Surrounded by his kind family, his days are now happy and lively. She is now a happy and lively person surrounded by her kind family, creating super-effective potions and instant magic. Occasional troubles can be easily solved with the knowledge of past lives! -What do you mean? Did I overdo it a little? I find myself being depended on by family and friends, and doing one out-of-this-world thing after another... What is normal in this world? The exhilarating fantasy of the strongest boy in another world!