Ryusei Takeshi, an overworked game developer, dies suddenly at the age of 27. But death is only the beginning of his story. Ryusei awakens in the afterlife, where the enigmatic Gideon offers him a second chance at life in the fantastical world of Trimaria.

Reborn as a Demon Lord, a class known for its immense power and dark reputation, Ryusei must navigate this strange new realm, filled with magic, adventure, and game-like elements. Armed with his knowledge of MMORPGs and his newfound demonic abilities, he sets out to uncover the mysteries of Trimaria and forge his own path as a hero.

Along the way, he'll forge unlikely alliances, and confront the very nature of good and evil itself. But as Ryusei delves deeper into the secrets of this world, he discovers that his choices, both in life and in death, have far-reaching consequences that will shape the fate of Trimaria and all who inhabit it.