The Hosokawa clan is one of strong Shugo Daimyo. The Hosokawa clan ruled Awa, Awazi, Bicchu, Izumi, Sanuki, Settsu, Tanba, Tosa and Yamashiro. The Hosokawa clan was one of the San-Kanrei, meaning three butlers, in Ashikaga shogunate. Hosokawa Katsumoto, the fifth, fought Onin war as the total generation. His son, Hosokawa Masamoto, took dictatorial power in Ashikaga shogunate but, from trouble of successor, he was assassinated in 1507. After his death, Hosokawa clan divided, fought each other and their power was weakend.

For a time they lived in the Hosokawa Gyobutei which was constructed in 1646. The Hosokawa Mansion is located in Kumamoto, near Kumamoto Castle. Both the castle and the mansion are tourist attractions, and the mansion has guided tours of the mansion grounds and relics. Among the relics is a tea cup used by the protagonist of the story of the 47 Ronin.