The story centers on Orun, a swordsman who changed to a mage class for the sake of the "Hero's Party" that he belonged to. He even developed a unique style of magic to support the party. But Oliver, Orun's childhood friend and the leader of the party, kicked Orun out of the party due to a lack of ability. His party members mocked him for being a "jack of all trades but master of none" and the party already found his successor. Disappointed, he parts ways with the party and begins solo activities as an explorer. Orun's fate changes dramatically with new encounters, and in order to protect those who have become important to him, he aims to take his "jack of all trades" skills to become the "ultimate all-rounder."