Although there was much sympathy for Yoritomo's call to arms, the clans were wary of openly supporting him, and an army of only 300 gathered at Ishibashiyama where he had raised his standard.

A force from the Miura clan, was prevented from reaching Yoritomo due to poor weather conditions which caused the Sakawa River near Kamakura to flood.

A further 300 soldiers under the command of Itō Sukechika skirted around the camp, attacking the Minamoto forces in the rear to cut off their way of retreat.

At the same time the defenders were aided by members of Ōba's forces who's loyalties were questionable, and they decided to disrupt the assault against the Minamoto, using the dark and stormy conditions to avoid detection.

[7] Yoritomo then fled by sea from Cape Manazuru to the Bōsō Peninsula in Awa Province[8] in the south of present-day Chiba Prefecture on September 28, 1180.