"Salaryman Kintaro" centers on Kintaro Yajima, a former leader of a biker gang who transitions into the corporate world after the death of his wife. Determined to provide a stable life for his young son, Kintaro takes on a job at Yamato Construction, a company facing internal corruption and moral decay. Despite his lack of formal education and rough demeanor, Kintaro’s unwavering sense of justice, physical strength, and straightforward personality make him a formidable presence in the workplace.

The narrative explores Kintaro’s journey as he confronts unethical practices within the company, often clashing with corrupt executives and colleagues who prioritize profit over integrity. His unorthodox methods and refusal to compromise his principles earn him both admiration and animosity. Kintaro’s interactions with coworkers, including his boss, President Yamato, and his rival, Vice President Asakura, highlight the tension between traditional corporate values and Kintaro’s idealistic approach to business and life.

Throughout the series, Kintaro’s past as a biker gang leader occasionally resurfaces, influencing his actions and decisions. His loyalty to his friends and family, particularly his son, serves as a driving force behind his determination to succeed in the corporate world while remaining true to himself. The story balances workplace drama with moments of personal reflection, showcasing Kintaro’s growth as he navigates the complexities of corporate life and his own moral code.

The series also delves into the lives of supporting characters, such as Kintaro’s colleagues and rivals, who are shaped by their interactions with him. Themes of loyalty, integrity, and the clash between individualism and corporate conformity are central to the narrative. "Salaryman Kintaro" presents a compelling exploration of one man’s struggle to uphold his values in a world often dominated by greed and corruption.