After burning himself out working for a deadly company, Takeuchi is reborn in the fantasy world of Edram—not as a person, but the greatest Demon Dragon in history. When he crosses paths with a group of awkward heroes, they are so astonished by his immense power that they quickly ask him to be their lord. However, Takeuchi realizes that while the "Hero Association" led by a Saintess claims to protect the world’s peace, in reality it is just a fraud working against the heroes by making them give up their money and enchanted items. The main character relives his life experience and, taking pity on the new apprentices, uses his dragon powers to change the world.