• The father of Japanese clocks.
• A master-less samurai born in Aki (west of Hiroshima Prefecture) in 1598, who studied in Kyoto. He was employed by the great Shogun Ieyasu Tokugawa in 1598 to repair a clock that had been presented to him. The clock had been presented during a visit by Korean ambassadors. He also produced a working replica of the damaged clock.
• TSUDA Sukezaemon Masayuki later lived in Nagoya, serving the Owari clan in what is now Aichi Prefecture, and was invited to work in an official capacity as the maintainer of clocks for the Tokugawa family in Owari, beginning in Genna 9 (1623). He died in 1638. His descendants continued to work as clockmakers and master blacksmiths.

The TSUDA Family Descendants of Clock Smiths

The TSUDA Sukezaemon and his ten generations of descendant worked as Tokei-shi for the Tokugawa Shogonate for 270 years !! Refer List of Wadokei Makers for details of the descendants.