Abstract
During the Edo period of Japan from early 17^<th> to late 19^<th> century, most institutions of various categories were patrimonial and technology and art were transferred inside specific families from generation to generation. Regarding the art of cannons, artillery and casting, due to long peaceful time until late 18^<th> century, the technology was not used for making cannons, but was used only for casting temple bells, monumental towers, etc. In early 19^<th> century, Choshu-han was the strongest Daimyo, and opened fire to allied foreign fleet in 1863. The Gunjis was a family of specialist in casting and artillery art in Choshu-han. Their history was described as an example of technology transfer inside of the family.
