In 1561, Takeda Shingen built Kaizu Castle in the Kawanakajima area, a large city that could accommodate tens of thousands of troops, posing a huge threat to Echigo. Kenshin heard the news and led an army of 16,000 Quickly dispatch troops to Kawanaka Island. Shingen led an army of 20,000 to come to the rescue, and the two sides formed a confrontation on Kawanaka Island. Kenshin led the army and was stationed on Mount Tsuma. Shingen followed the advice of military adviser Yamamoto Kansuke and adopted the "woodpecker tactics". He asked generals Takasaka and Baba to lead 12,000 troops as a special force, and took advantage of the night to circle behind the Uesugi army. At the same time, they attacked the Uesugi army with eight thousand soldiers and horses. However, when Kenshin observed the Takeda military formation in the early morning, he found that the amount of smoke was significantly reduced. Therefore, he saw through Shingen's plan and took the lead. He led 16,000 troops and horses, formed a "car hanging" formation, and launched an attack on the empty Takeda main formation. Shingen hurriedly set up the "Crane Wings" formation to fight. The fighting between the two sides was extremely fierce. Takeda's army was outnumbered. Shingen's military advisor Yamamoto Kansuke, his brother Takeda Nobushige, and his general Hatsukano Gengoro were killed on the battlefield. However, Takeda Shingen stood firm behind the formation and remained motionless. , the Takeda Army was inspired by the general's confidence and never retreated. At noon, the 12,000-strong Takeda Army Rangers finally circled behind the Uesugi Army and surrounded the Uesugi Army together with the main formation. Upon seeing this, Kenshin personally led Hatamoto's troops into Takeda's base camp. The two fought for three rounds. Shingen was stabbed on the left shoulder by Kenshin, but was rescued by Hatamoto. Seeing that the situation was over, Kenshin led his troops to break through and withdrew from Kawanaka Island. The Fourth Battle of Kawanakajima came to an end. Both sides had their own gains and losses, and who won and who lost has become a topic of endless debate among Japanese historians.

The personalities and hobbies of the two main generals in the Battle of Kawanakajima: Takeda Shingen and Uesugi Kenshin are almost completely opposite. Both of them were famous generals in Japan's Warring States Period. Uesugi Kenshin was proficient in tactics and had strong command. He created his own "Chexuan" formation. He fought seventy battles in his life, with forty-three wins, two defeats, and twenty-five draws. He has great martial arts and is known as the "God of War". He loves taking risks in battle and does not adhere to the correct methods of war. When attacking, he often takes the lead and rushes to the front, defeating the enemy in one fell swoop with a fierce offensive. Another overlord, Oda Nobunaga, once said with lingering fear: "Kenshin is as brave as the rebirth of Mori Shiten. Who in the world can resist him? If Kenshin comes, I will wear a dress, shake a fan, and ride alone to meet the road." . He said, "I am here to express my sincerity." Kenshin should not break my bones to tell the world! He often prays and meditates at Bishamonten Hall, and when he goes into battle, the name of Bishamonten will always be written on the military flag. He is indeed a devout believer. He is upright and upright by nature. He hates conspiracies and conspiracies. He has no ambition to expand his territory or conquer the world. He has always fought to protect the justice in his heart throughout his life. He never flirted with women throughout his life, but he loved drinking. He never left his hand with a cup when he was marching and fighting. He died of illness at the age of 49. Before his death, he wrote a poem: "I drink a glass of wine at the age of 49, and I get drunk at the age of 49. I don't know whether I will live or die. The years are just like a dream." Kenshin's art of war, later called "Echigo-ryu", was divided into two branches: Sawasaki Keimi's "Kaito" and Usami Yoshiken's "Shintoku".

Takeda Shingen paid more attention to strategy. He had no personal hobbies. He worked hard on state affairs all his life and worked hard without complaint. During his rule in Kai, he controlled floods, developed mines, cultivated talents, built diplomatic alliances, and formed the Kai Army. The "Twenty-Four Takeda Generals" were the most elite group of retainers at that time. Before a battle, Shingen would often come up with various strategies such as rumors and instigation of rebellion to weaken the opponent's strength and enhance his own chances of winning. He often fought decisively abroad to avoid affecting his own people. When fighting, he always takes command of his own formation and never goes into battle easily. Shingen was very cautious in his battles and rarely rashly attacked with his entire army. Instead, he adopted the "woodpecker tactics", using part of his troops to lure, test, or surround the enemy, and use patient small-scale battles to wear down the enemy's morale and induce the enemy to reveal weaknesses. Then use the elite troops to win with one blow. Although the "Woodpecker Tactics" was seen through by Kenshin Uesugi, Shingen did achieve many victories with this tactic. Shingen's famous saying is: "To win an ordinary army, five points is considered superior, seven points is considered medium, and ten points is considered inferior. Why? Five points breeds motivation, seven points breeds arrogance, and even if you win a battle, if you are arrogant, you will lose in the next battle. ." He loved to read "Sun Tzu's Art of War" and wrote on the military flag the words "as fast as the wind, as slow as the forest, as aggressive as the fire, and as motionless as the mountain" in the "Art of War", and simplified it into the four-character combat rule of "Wind, Forest, and Fire". .

There are many explanations for the four words "Fenglinhuoshan". The generally accepted explanation is: the light cavalry is as fast as the wind and is responsible for reconnaissance, disruption, forward and other tasks. The infantry (including shooters) are as advanced as the forest and is responsible for forming defenses and occupying buildings. Waiting for the mission, the heavy cavalry "Akabei" charged like fire and was responsible for the key blow that decided the battle. Shingen himself was as immobile as a mountain, taking an overall view of the overall situation and commanding the entire army. Shingen was ambitious. Although he was born in a poor and small Kai, he worked hard all his life and determined to unify the world and end the troubled times. However, his ambition was not fulfilled and he died of illness during the battle. He left a poem: "I will return to heaven and earth with this body and bones, and I will not touch the world of mortals." Merry", died at the age of fifty-three. Shingen's art of war was later inherited by the "Phoenix of Military Strategies" Kohata Keiken, and was known as the "Koshu-ryu" in history.

Sun Tzu's Art of War says, "A good attacker moves above the nine heavens, and a good defender hides under the nine earths." The film is named after "Heaven and Earth", perhaps to describe the two overlords respectively. Character and experience: Qianxin is strong and brave, Xinxuan is pliable, Xinxuan is martial, Xinxuan is wise, Xinxuan has a good reputation, Xinxuan values ????profit, Xinxuan uses miracles, Xinxuan uses integrity, Xinxuan is as sharp as the thunder of the sky, and Xinxuan is as generous as the earth. The five battles of Kawanakajima took the two of them most of their lives and efforts. Even though both of them were wizards of the generation, (several later overlords, such as Oda Nobunaga, Tokugawa Ieyasu, etc., were all in front of their troops). Vulnerable), but the two of them restrained each other, and both missed the opportunity to dominate the world and failed to make greater achievements in troubled times. Although there is a sigh for him that "how can he be brilliant when he is born with excellence", but in the long history, dynasties have changed countless times. On the contrary, he can meet his opponents in chess, meet good talents, and play a wonderful rivalry, which makes him happy in this life. , leaving his name in history, making future generations admire him endlessly and hate him at the same time.