A full-fledged biography of a man who dedicated his life to the study of his beloved dogs. In the early Showa era, there lived a man in his home in Jiyugaoka, Tokyo, who, in addition to dozens of dogs, lived with canids such as Korean wolves, jackals, tanuki, foxes, hyenas, and civets, and studied their ecology. He ate and slept with his favorite dogs, and walked a tamed wolf in Ginza. He belonged to no academic society, and continued his research life alone. His figure was introduced in the satirical cartoonist Hidezō Kondō's "Showa Kijin-den" as "Yonekichi Hiraiwa of animals," alongside "Tomitaro Makino of plants." From the Taisho era to the early Showa era, during the war, the post-war confusion, the high-growth period, and into the modern era—. A full-fledged biography of a man who loved dogs and was absorbed in their study during a time of intense change. Winner of the 12th Shogakukan Nonfiction Award.