"Raised by the Demon Kings!" is a fantasy manga series that centers on a young human boy named Hiro, who is adopted and raised by the seven Demon Kings after being abandoned as a child. The Demon Kings, each representing a different sin and possessing immense power, rule over their respective domains in the demon world. Despite their fearsome reputations, they take Hiro under their care, teaching him their ways and nurturing him with a blend of affection and discipline.

The story explores Hiro's growth as he navigates the complexities of living among demons while retaining his human identity. Each Demon King imparts unique lessons and skills, shaping Hiro into a formidable individual who bridges the gap between humans and demons. As Hiro matures, he begins to uncover secrets about his origins and the true nature of the Demon Kings, leading to conflicts that challenge his loyalties and understanding of the world.

The narrative delves into themes of identity, morality, and the coexistence of opposing forces. Hiro's relationships with the Demon Kings are central to the plot, with each king embodying distinct traits and philosophies that influence his development. The series balances moments of humor, action, and emotional depth, creating a dynamic exploration of Hiro's journey as he grapples with his dual heritage and the responsibilities it entails.

Key characters include Lucifer, the prideful and authoritative leader of the Demon Kings; Asmodeus, who embodies lust and teaches Hiro about desire and restraint; and Beelzebub, representing gluttony and offering lessons on indulgence and control. The interactions between Hiro and the Demon Kings drive much of the story, highlighting their individual personalities and the evolving dynamics of their unconventional family.

As the plot progresses, external threats emerge, including human factions seeking to exploit Hiro's unique position and rival demonic forces aiming to overthrow the Demon Kings. These conflicts test Hiro's resolve and force him to confront the consequences of his upbringing. The series weaves together elements of adventure, self-discovery, and the clash between human and demonic worlds, creating a rich and engaging narrative.