An anime adaptation was created by Madhouse, with 24 episodes airing between 1998 and 1999 in Japan on Nippon Television.An additional 15 episodes were created and released as original video animations, bringing the total to 39 episodes. Naoki Urasawa and Takashi Nagasaki created a sequel to the series, titled Master Keaton Remaster (MASTERキートン Reマスター). Set 20 years after the original series ended, it ran in Big Comic Original from 2012 to 2014 and was collected into a single volume.
The anime and OVA series were dubbed into English and released in North America by Pioneer Entertainment. Viz Media began releasing the manga in North America in 2014.The story revolves around Taichi Hiraga-Keaton (平賀＝キートン・太一 Hiraga-Kīton Taichi), the son of Japanese zoologist Taihei Hiraga (平賀太平 Hiraga Tahei) 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.
At Oxford, Keaton met and later married his wife, who was a mathematics student at Somerville College. The couple later divorced, with Keaton leaving his five-year-old daughter Yuriko (百合子) in her mother's care. After leaving Oxford, Keaton joined the British Army and became a member of the SAS, holding the post of survival instructor 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 extremely successful as an insurance investigator, his dream is to continue his archaeological research into the possible