However, the siege developed into a war of attrition, and after serious setbacks such as the sudden death of his relative Shingen, from whom he had been hoping for assistance and the defeats by Oda of the alliance powers, such as the Asakura and the Asai, Kennyo came to realize the hardship of continuous war and asked court to be an intermediary for peace.
しかし、長期にわたる攻囲戦によって次第に疲弊する一方、縁戚関係にあった信玄の支援を期待していたが、信玄の急死が大きな痛手となり、さらに朝倉、浅井などの同盟勢力が次々と織田氏によって滅ぼされたため抗戦継続の困難を悟り朝廷に和平の仲介役を依頼した。