A battle fought between Sagara clan forces led by Sagara Yoshihi and Aso clan forces led by Kai Souun at Mifune Castle. The Sagara clan had formerly joined forces with the Aso clan to oppose the 1578 full-scale Shimazu invasion of Higo, but had been defeated by the Shimazu clan in 1581 and forced to fight their former allies.

In the early morning of December 27, 1581, Souun secretly advanced his troops in two groups to Hibikigahara, where Yoshihi was camped, himself leading the main force with guns at the front. He managed to catch Yoshihi in a surprise pincer movement and killed him and about 300 of his soldiers.