Taichi Hiraga-Keaton is the son of Japanese zoologist Taihei Hiraga and well-born Englishwoman Patricia Keaton. Keaton's parents separated when he was five, and young Taichi moved back to England with his mother. As an adult, he studied archeology at Oxford University, in part under the tutelage of Professor Yuri Scott.

After leaving Oxford, Keaton joined the British Army and became a member of the SAS, reaching the rank of master sergeant and seeing combat in the Falklands War and as one of the team members that responded to the Iranian Embassy incident.

His combat training serves him in good stead as an insurance investigator for the prestigious Lloyd's of London where he is known for his abilities and his unorthodox methods of investigation.

In addition to his work for Lloyd's, Keaton and his friend Daniel O'Connell operate their own insurance investigation agency headquartered in London. Even though Keaton is fairly successful as an insurance investigator, his dream is to continue his archaeological research into the possible origins of an ancient European civilization in the Danube River basin.