As previously described, their interest was in accord with each other; Nobunaga sought reinforcement from Ieyasu when he was in a critical situation by the anti-Nobunaga network of Shogun Yoshiaki; Ieyasu did from Nobunaga when he needed to win successfully through a fight with his powerful enemy Shingen TAKEDA.
このように、お互いの利害が一致して信長は将軍・義昭によって信長包囲網が敷かれたときの危機的状況から家康の援軍を、家康は武田信玄という強敵との戦いを勝ち抜くということから信長の援軍を求めたのである。