Born in 1728 into the family of a low-ranking samurai in Takamatsu Domain, Sanuki Province (Kagawa). Studying in Nagasaki, he absorbed Dutch natural history, medicine, and engineering; in Edo he became a leading figure in herbalism and natural science, organizing scholarly exhibition meetings. But his true genius lay in invention. Around 1770, he restored and improved a static-electricity generator called "Elekiter" that Dutch traders had brought to Japan and left broken, attempting to use it as a medical instrument — Japan's first experiment with electricity. He also researched asbestos fiber ("fire-resistant cloth") and attempted to develop it practically. Under the pen name Furaikenjin he wrote satirical gesaku fiction that became popular. He is also credited with inventing the tradition of eating eel on "Doyo no Ushi no Hi" (Midsummer Day of the Ox) — supposedly after an eel restaurant owner asked him how to boost summer sales, and he devised a sign reading "Today is the Day of the Ox." This genius of bottomless creativity met a tragic end: in 1780, he accidentally stabbed an acquaintance, was imprisoned, and died in jail at 52.

A monster of curiosity. Unable to settle on one thing, he dabbled in invention, literature, natural history, and commerce — yet produced first-rate results in each. A complex genius who combined Edo wit and nonchalance with an oversized ego.

His restoration of the Elekiter was the starting point of electrical research in Japan. The "eel on Doyo no Ushi no Hi" tradition he created lives on today. His life — embodying the light and darkness of genius — has become prime material for novels and dramas.