Motochika was an important Hosokawa retainer and was given the governership of Sanuki province by Hosokawa Masamoto around 1494. He defended Masamoto against the forces of Miyoshi Yukinaga in 1506 but came to be at odds with his lord. Around this time, Masanaga had censured Motochika for heavy-handed efforts to secure personal income from Yamashiro province. Motochika supported Hosokawa Sumiyuki (one of Masamoto's adopted sons) and in 1507 the two attacked Masamoto's home and killed him in his bath. Sumiyuki was thus established as Masanaga's successor but this lasted barely a month. Masamoto's adopted son Sumimoto turned to his ally, Miyoshi Nagateru, and the latter defeated and killed Motochika and Sumiyuki in battle near Kyoto.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005