"Revenger" is set in a fictionalized version of Japan during the late Edo period, blending historical elements with a unique narrative of vengeance and justice. The story centers around Kurima Raizou, a skilled assassin who becomes disillusioned with his life of killing. After a fateful encounter, he joins a group known as the Revengers, a secretive organization that takes on contracts to avenge those who have been wronged by corrupt individuals. The Revengers operate outside the law, targeting powerful figures who exploit the weak and vulnerable.

The group is led by Yuen Usui, a mysterious and charismatic figure who recruits Raizou after recognizing his skills and moral conflict. Other key members include Nio, a sharp-witted and resourceful strategist, and Teppa, a stoic and physically imposing enforcer. Together, they navigate a world rife with political intrigue, betrayal, and moral ambiguity, carrying out missions that often blur the line between justice and revenge.

The narrative explores themes of retribution, redemption, and the consequences of violence. Raizou’s internal struggle with his past as an assassin and his desire for a more meaningful existence drives much of the character development. The series delves into the backstories of the Revengers, revealing their personal motivations and the events that led them to join the group. Each mission they undertake sheds light on the darker aspects of society, from corrupt officials to exploitative merchants, while also challenging their own moral compasses.

As the story progresses, the Revengers face increasingly complex and dangerous adversaries, forcing them to confront their own limits and the ethical implications of their actions. The series balances action-packed sequences with moments of introspection, creating a layered narrative that examines the cost of vengeance and the possibility of redemption. The interplay between the characters and their evolving relationships adds depth to the story, making "Revenger" a compelling exploration of justice in a morally ambiguous world.