Lucifer, a powerful Archangel, is cast out of Heaven for rebelling against God.
She falls to Hell, where she encounters Leviathan, an aspiring Demon Lord.
Together, they plan to overthrow the Seven Sins, the rulers of Hell.
However, they are defeated, and Lucifer is cursed with a Garb of Punishment, weakening her powers and transforming her into a Demon Lord.
Seeking revenge, Lucifer, accompanied by Leviathan, travels to Earth.
There, she enslaves a human girl named Maria.
Lucifer, Leviathan, and Maria embark on a journey to defeat the Seven Sins and break the curse of the Garb of Punishment.