A boy raised by gods will be the strongest.

Baby Will was abandoned drifting through a river in a small boat, when Reus, the God of omnipotence, picked him up and was taken to a mountain where the gods lived. After displaying potential to the three gods: The God of swords 'Ronin', The Goddess of Health 'Miria', and The God of Magic 'Vandal'; they all three decided on what he should become, having their own vision in mind:

"This child has sword talent, once he grows up I'll have him be a warrior swordsman." "No, this is the world's kindest child, and he'll be the world's greatest healer." "No, this child is a rather intelligent, I shall teach him my magic and make him the ultimate magician."

While all three gods are divided and fighting, Reus tells them to cut it out and settle the argument by having each God take turns in teaching him. Through the curriculum given to him by the God of the Sword, Goddess of Healing, and the God of Sorcery, Will becomes the strongest and sets out on his journey at 14.