"The Tale of the Outcasts" is a manga series set in an alternate version of early 20th-century England, blending historical elements with supernatural themes. The narrative centers on Wisteria, a young orphan girl living in poverty, and Marbas, a powerful but cursed immortal being known as a "Beast." Wisteria's life takes a dramatic turn when she encounters Marbas, who offers her a pact: he will grant her immense power and protection in exchange for her lifespan. Desperate for a way to escape her bleak existence, Wisteria accepts, forming a bond that intertwines their fates.

Marbas, once a revered figure among Beasts, is now an outcast due to his refusal to serve the oppressive ruling class of his kind. His curse binds him to a life of solitude, but Wisteria's presence begins to challenge his isolation. Together, they navigate a world where humans and Beasts coexist uneasily, with Beasts often exploiting humans for their lifespans to sustain their power. The series explores themes of inequality, redemption, and the search for belonging as Wisteria and Marbas confront both human and supernatural adversaries.

The story introduces a diverse cast of characters, including other Beasts with their own motivations and struggles. Among them is Snow, a Beast who initially appears as an antagonist but later becomes a complex ally. The narrative also delves into the political dynamics between humans and Beasts, revealing a society rife with corruption and exploitation. Wisteria's growth from a vulnerable orphan to a determined and compassionate individual forms the emotional core of the series, while Marbas' journey explores themes of guilt, atonement, and the possibility of change.

As the plot unfolds, Wisteria and Marbas uncover secrets about the origins of the Beasts and the true nature of their world. Their bond deepens, challenging the established order and forcing both characters to confront their pasts. The series balances action, mystery, and emotional depth, creating a compelling narrative that examines the complexities of power, loyalty, and the human condition within a richly imagined supernatural setting.