According to the memorandum of the Sata family, their ancestor, Sata Muneharu, took part in the Shimabara War to attack on Hara-jo Castle as a captain of a gun squad of the Tachibana army in 1637. For breaking into the castle, bundles of bamboo were needed. So, he brought a cooper, Kato Yosuke, as a subordinate. However, both of them died in the battle. Muneharu was shot while Yosuke was struck by stones which the enemy dropped when he tried to break into the castle.
The same story has been passed down in the Kato family of coopers. Because of this history, it seems that both of the families have had a close relationship since then.
This memorandum is considered to be a copy which was made to certify the story of the Kato family.