"Mad Bull 34" is a gritty and action-packed anime series set in the crime-ridden streets of New York City, specifically focusing on the 34th precinct. The narrative centers on two police officers, Daizaburo "Eddie" Ban and John Estes, who form an unconventional partnership. Eddie, a young and idealistic rookie from Japan, is assigned to work with John, a hardened and brutal veteran cop known as "Mad Bull." Their contrasting approaches to law enforcement create a dynamic tension throughout the series.

John Estes operates with a ruthless, no-holds-barred mentality, often resorting to extreme violence to combat crime. His methods are unorthodox and frequently cross ethical boundaries, but they are effective in dealing with the dangerous criminals plaguing the city. Eddie, on the other hand, initially struggles with John's violent tactics, as they clash with his sense of justice and morality. Over time, Eddie begins to understand the harsh realities of their environment and the necessity of John's methods, though he never fully abandons his principles.

The series delves into various criminal elements, including drug trafficking, organized crime, and corruption within the police force. Each episode presents a new case or challenge, often highlighting the moral ambiguity of their work. The duo faces off against a range of adversaries, from street-level thugs to powerful crime syndicates, with John's brute force and Eddie's growing adaptability proving crucial in their missions.

Supporting characters include other members of the 34th precinct, such as Chief Bison, who often finds himself at odds with John's methods but acknowledges their effectiveness. The series also explores the personal lives of the main characters, providing glimpses into their motivations and struggles outside of their police work.

"Mad Bull 34" is characterized by its intense action sequences, graphic violence, and a dark, often cynical portrayal of urban crime. The narrative does not shy away from depicting the brutal realities of law enforcement in a city overrun by crime, making it a stark and uncompromising series. The relationship between Eddie and John serves as the emotional core, with their evolving partnership reflecting the broader themes of justice, morality, and survival in a chaotic world.