After Asahina Taisuke and Yakai Chiyomoto agreed to seek reinforcements together, they felt they couldn't just sit here stupidly waiting for help. Otherwise, when the reinforcements finally arrived, they'd really have no face left. So they decided to keep attacking—or at least make it look like they were still attacking.
But launching a frontal assault on a stronghold was just too hard. If the defenders had tough fighting spirit, the difficulty doubled. They didn't want to throw flesh and blood against concrete again, but the siege methods in Japan of this era were limited to only a few: "fire attack," "water attack," "underground tunneling," or "bribing insider traitors to open the gates."
