A 34-year-old NEET gets killed in a traffic accident and finds himself in a world of magic. Rather than waking up as a full-grown mage, he gets reincarnated as a newborn baby, retaining the memories of his past life. Before he can even properly move his body, he resolves to never make the same mistakes he made in his first life ever again and instead live a life with no regrets with the new one that was given to him. Because he has the knowledge of a middle-aged man, by the age of two, he has already become a prodigy and possesses power unthinkable for anyone his age and even older. Thus begins the chronicles of Rudeus Greyrat, son of swordsman Paul and healer Zenith, as he enters a new world to become the strongest mage known to man, with powers rivaling even the gods themselves.