The Shimizu clan was granted shuinjo (shogunate license for trading) from the Tokugawa shogunate, as the Shimizu clan was the native place of Ieyasu TOKUGAWA's concubine, Okame no Kata, (who was the real mother of Yoshinao TOKUGAWA, an ancestor of the Owari Tokugawa family.)
また、徳川家康の側室お亀の方（尾張徳川家の祖徳川義直の生母）は志村氏の出身であることから、江戸幕府から朱印状を得た。