Matsudaira Sadanobu
Seizan was acquainted with Matsudaira Sadanobu, chief councilor to the Tokugawa shogunate from 1787 to 1793, who initiated the Kansei Reforms. He was also interested in the Western learning that entered Japan via trading contacts with Dutch merchants (a globe that he owned is still preserved in the Matsura Historical Museum), and a collector of popular novels and paintings by masters of ukiyo-e art.