Sugita Genpaku was well-known for his broad social network, which owed much to his easygoing nature. One of his more unusual friends, however, was Hiraga Gen'nai -- dubbed Japan's answer to Leonardo da Vinci.
Gen'nai was an inventor, a playwright, a naturalist, a Western-style painter, an essayist -- and a humbug. Born in 1728, the third son of a foot soldier in Shikoku's Takamatsu domain, he studied rangaku (Dutch learning) in Nagasaki and moved to Edo where he amazed -- and amused -- not only the townspeople and scholars of rangaku, but also the shogunal authorities with his inventions and catchy promotional lines for them.
One of his most well-known gadgets was elektriciteit, a type of frictional electricity generator, which was originally presented to the Tokugawa Shogunate by a Dutch mission in 1751, and was later customized by Gen'nai. Others included fireproof clothes made of asbestos called kakanfu, a thermometer, a pedometer and a propeller.