Motosuna was a younger brother of Môri Motonari, though the two shared a different mother. Adopted into the Sôgô family, Mototsuna opposed Motonari's assumption of leadership of the Môri house in 1523. Though he gathered a number of notable Môri retainers to his cause, he was captured by Motonari and beheaded.
References
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005