News of victory spread like a spring breeze to the Imagawa camp at Okehazama. Hearing the news of the successive victories at Ōtaka and Narumi, Imagawa Yoshimoto burst into laughter. He immediately ordered Matsudaira Motoyasu to retreat to Ōtaka Castle for rest and recuperation and ordered Udono Nagateru to lead the vanguard troops directly toward Kasadera. Confident of victory, he completely relaxed his guard, ensconced in the valley of Okehazama, enjoying the wine and delicacies offered by the nearby shrines and temples. A sense of complacency permeated the entire army.
However, death was already quietly approaching.
Oda Nobunaga, personally led by Nakajima's elite troops, took advantage of the sudden surge of dark clouds and torrential rain to silently advance towards the Imagawa main camp. The fierce wind and rain not only muffled the sound of horse hooves, but the Oda soldiers also interpreted it as a divine wind blessed by Atsuta Daimyojin, boosting morale. Nobunaga personally led 300 cavalrymen, thrusting like a poisoned dagger straight into Imagawa Yoshimoto's heart!
The decisive battle erupted amidst thunder and lightning. The Oda army broke through four or five waves of interceptors, but their own generals fell one after another. Seeing his trusted associates dwindling, Oda Nobunaga resolutely dismounted, brandished his sword, and shouted, "Follow me!" With the commander leading the charge, the remaining samurai's blood raced, unleashing an astonishing burst of fighting power.
In the midst of the melee, the samurai Kodaira thrust his spear straight at Imagawa Yoshimoto, but his sword, Yoshimoto Samamonji, severed the spear shaft, wounding Yoshimoto's knee. Just as Yoshimoto thought he had averted the crisis, another Oda general, Mori Hidetaka, swooped in like a ghost. With a flash of his sword, Imagawa Yoshimoto, the master of the East China Sea, was beheaded!
Mori Hidetaka raised the head, still etched with a look of astonishment, high in the air and roared three times with all his might: "Imagawa Yoshimoto, capture it!"
The cry was like thunder, instantly crushing the will of the Imagawa army. News of their leader's death spread like a plague, and the 40,000-man army, previously in perfect order, collapsed. Oda Nobunaga ordered no pursuit but calmly withdrew his troops. This fateful battle, which determined the fate of Tōkaidō, lasted only two hours, yet, like legendary battles like Julu and Chibi in China, it became a classic example of a small force triumphing over a large one, one that will live forever in history.
On his triumphant return, Nobunaga presented a sacred horse to Atsuta Shrine to thank the gods for their divine wind assistance.
Yoshimoto's death left the Imagawa clan with a difficult situation to deal with. Seeing the situation hopeless, the Ikko sect followers who had come to support the battle quietly dispersed. Matsudaira Motoyasu of Ōtaka Castle, upon hearing the tragic news, retreated to Okazaki overnight. Only Okabe Motonobu of Narumi Castle remained determined to hold out. Only after the persuasion of Oda Nobunaga and the orders of his young lord, Imagawa Ujizane, did Okabe finally agree to withdraw.
Before departing, this loyal samurai made a bold request: he demanded the return of his former master's head so that he could be buried in his homeland. Impressed by his loyalty, Nobunaga not only returned the head but also sent ten monks to offer condolences. Upon returning to Suruga, Okabe Motonobu was commended by Imagawa Ujizane for this act, but this was the last trace of honor left for the family.
Imagawa Yoshimoto's death was like a lever that shook the Tōkaidō landscape. His successor, Imagawa Ujizane, was incompetent and incompetent, neither seeking to avenge his father nor employing capable men. His loyal ministers and generals repeatedly tried to persuade him, but to no avail. Instead, they left, disheartened by his inconsistent rewards and punishments and his capricious moods.
Meanwhile, Matsudaira Motoyasu, despite his repeated admonitions, secretly gathered strength. Those who had defected from the Imagawa clan flocked to the side of this patient hero. A new star was quietly rising from the ruins of Tōkaidō, poised to illuminate another turbulent era.