In the run-up to hostilities, Nabeshima Naoshige of Saga Domain intended to support the Tokugawa; however, his son Katsushige was present at Mitsunari's war council on 17 August and swayed him towards joining the Western Army. However, while the Nabeshima forces participated in some operations on Honshu including the assaults on Fushimi and Annotsu, Naoshige eventually recalled Katsushige to Kyūshū prior to the decisive battle at Sekigahara and switched allegiance to the Eastern Army. Tachibana clan head Tachibana Muneshige also joined the Western Army forces under the Mōri clan, leaving the defense of their hegemon Ōtomo clan's territory to his wife and co-clan head Ginchiyo. However, following the defeat at Sekigahara which Muneshige could not attend due to the protracted siege of Ōtsu, Muneshige also returned to defend his Kyūshū holdings.
