In order to counterattack the large bakufu army, which came up to the north from Hannan (south of Osaka), in a narrow area so, that their own troops, inferior in number, could fight off a larger army of the bakufu, the troop core marched to the Yao district.
豊臣方は阪南から北上してくる幕府の大軍を、数で劣る自軍でも撃退できるよう狭い地域で迎え撃つべく、主力軍が八尾方面に進軍。