"Master Keaton" centers on Taichi Hiraga-Keaton, a former SAS soldier turned insurance investigator with a background in archaeology. Keaton’s unique skill set, blending military training, academic expertise, and sharp deductive reasoning, allows him to tackle a wide range of cases across Europe and beyond. The series is episodic, with each episode presenting a self-contained story that often intertwines mystery, adventure, and human drama.

Keaton’s investigations frequently lead him into dangerous situations, from uncovering insurance fraud to solving historical mysteries and rescuing individuals in peril. His work often takes him to remote locations, where his archaeological knowledge proves invaluable. The narrative explores themes of cultural heritage, morality, and the complexities of human nature, often delving into the personal histories of those he encounters.

Supporting characters include Keaton’s estranged wife, Yuriko, and their daughter, Yuriko, who occasionally appear, providing glimpses into his personal life and the emotional toll of his nomadic career. Keaton’s father, Takaaki Hiraga, a renowned zoologist, also plays a role, offering intellectual sparring and contrasting perspectives on life and science.

The series balances action with introspection, showcasing Keaton’s resourcefulness and compassion. His ability to navigate both physical and emotional challenges makes him a compelling protagonist. The episodic structure allows for a diverse range of stories, from lighthearted adventures to poignant explorations of loss and redemption. "Master Keaton" stands out for its blend of intellectual depth, historical intrigue, and character-driven storytelling.