Site of Kanayama Castle
Yuki Yaheiji (1544–unknown) was a retainer of Konishi Yukinaga (1555–1600), the Christian daimyo of Higo Province (modern-day Kumamoto Prefecture). When Konishi was executed for fighting on the losing side at the Battle of Sekigahara in 1600, Yuki switched his allegiance to Arima Harunobu (1567–1612), the Christian daimyo of Shimabara who had fought on the winning side. Arima presented Yuki with a domain that included Kanayama Castle—an okajiro, or hilltop castle built on a plain—in 1602.
In 1612, the shogun had Arima executed for his part in a corruption scandal, replacing him with his son Arima Naozumi (1586–1641), who turned against Christianity to curry favor with the shogun. When Yuki refused to follow suit and abandon his faith, he was driven into exile. The castle is known locally as Yukijo (“Yuki’s Castle”).