The Sengoku Period, or better known as the “Warring States Period,” refers to the time between mid-fifteenth to late sixteenth centuries where bloodshed and political intrigue dominated every aspect of Japanese life. During the Sengoku Period, the concept and reality of Japanese unity was non-existent as daimyo were constantly battling for power with one another, and many of the major historical events of this period were either caused by or resulted in betrayal. As with every major historical event, there is always a story standing behind events but nothing in Japanese history is more tangled or bloody than the underlying circumstances of the Sengoku Period. 

In 1338, the legendary and fearless warrior Ashikaga Takauji, in a daring coupe, seized control of Kyoto from the Emperor of Japan and declared himself the shogunate, the godhead of the military and total dictator of Japan. This establishment of the Ashikaga shogunate marked the beginning of the Muromachi period of Japanese history, where trade relations with China dominated Japanese politics and economy. By establishing these trade relations with China, the Ashikaga shogunate successfully ended the incessant warring between the rival Northern and Southern Imperial Courts, thus promoting a greater sense of the arts. Out of this, the Feudal landlords or daimyo were born. They were vastly powerful controlling the military, police, and economy as they lorded over their lands with iron fists and wills forged of steel. Unfortunately for the Ashikaga shogunate, over time its successors grew weaker and weaker, each time further losing their grip on the government’s power and placing more resources and power into the hands of the daimyo. The change in trade relations with China and the vast increase in the power held by the daimyo led to the Sengoku Period, which has been marked in the annals of time as beginning with the Onin War (1467-1477). The Onin War began as a small scale local conflict over the succession of the Ashikaga shogunate, which quickly blossomed into a decade-long war between rivaling daimyo vying for control of the shogunate. At the end, Kyoto was left absolutely decimated as in the end the Ashikaga shogunate held power in name only. For ages after, rivaling daimyo would fight for control of the puppet government propped up by the title of Ashikaga shogunate – although by this point, controlling the court meant very little in any way, as essentially all actual power had been scattered among the many daimyo ruling and making their wills known across Japan. After several decades of boisterous infighting, the bloody and ruinous Sengoku Period came to its penultimate chapter with the rise of three legendary warriors: Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu.

…nothing in Japanese history is more tangled or bloody than the underlying circumstances of the Sengoku Period.
The first of Japan’s three mythical unifiers, Oda Nobunaga, was the leader of one of the smallest clans in Sengoku Japan: the Oda. With great grace and speed, Nobunaga grew his power by destroying all his opponents using only wit and strategy. In the Battle of Okehazama, Nobunaga defeated the combined forces of the Imagawa and the Matsudaira clans, which numbered about 40,000 soldiers, with only a paltry force of 3,000 by using a fierce storm to hide the advance of his troops and commencing an overwhelming surprise attack. After severing ties with the weakened and demoralized Imagawa clan, the Matsudaira clan chose to forge an everlasting alliance and pledged fealty to the Oda, bringing to an end decades of hostility. Though these developments were relatively small in scale compared to the death and destruction that came from other clans warring, what mattered most is Oda Nobunaga’s epiphany that he had extremely adept generals such as Toyotomi Hideyoshi and Tokugawa Ieyasu responsible for his militaristic and diplomatic success. For the first time in his life, Nobunaga saw the possibility of what had long been considered an impossible future: the ultimate unification of Japan. After taking total control of central Japan, Nobunaga set his sights on the capital city of Kyoto. In 1568, his troops descended on the capital, crushing all opposition that stood in their way. With the assistance of European technology and weapons, Nobunaga spent the next five years cutting down any daimyo that dared oppose him, including the legendary general Takeda Shingen, long said to have held the most deadly and powerful samurai army in Japan under his command. Shingen was a strategic genius and his years of military experience meant he was easily the most qualified and dangerous to Nobunaga’s dream of unifying Japan. Shingen gained control of Suruga and western Kozuke and led a force of over 30,000 warriors into territories to make a stand against Nobunaga’s war machine. Set on a collision course with Nobunaga’s ambitions, Shingen engaged with Oda Nobunaga’s and Tokugawa Ieyasu’s combined forces at the Battle of Mikatagahara and was victorious. After defeating Ieyasu, Shingen stopped his advance and shortly after entering Mikawa province was found dead in his encampment. 

Takeda Shingen would not be the one to take down Oda Nobunaga, but threats to his dream still loomed on the horizon. Despite his path to victory clear and his dream so close to being realized, Nobunaga’s quick rise to power stopped short in 1582 when one of his vassals, Akechi Mitsuhide, assassinated him. Mitsuhide had a falling out with Nobunaga in the past partially due to a member of his family being murdered as a result of Nobunaga breaking peace terms with the Hatano clan. For nearly four years Mitsuhide dwelled on the actions of Nobunaga and plotted his revenge. In 1582, Mitsuhide was ordered to march westward and assist in the fighting of the Mori clan. Instead, Mitsuhide assembled an army of 13,000 and marched on Nobunaga’s fortified position at Honno-ji. Mitsuhide’s forces surrounded the temple and set it ablaze while both Nobunaga and his son were killed in the fighting that ensued. The great betrayal which occurred turned the capital upside down as Mitsuhide quickly moved to declare his heritage made him shogunate and began looting to reward his men for their loyalty for their part in the assassination of Nobunaga. Mitsuhide began making gestures of peace and friendship towards the clans and the imperial court in an attempt to garner support for and cement his place as shogunate. While the court was panicked at the coupe that Mitsuhide began with the assassination of Nobunaga, the imperial court and clans were not easily swayed, but Mitsuhide felt he had time on his side as one of Nobunaga’s chief generals Toyotomi Hideyoshi was currently occupied fighting with his army against the Mori clan. He was mistaken. 

As soon as word of his lord’s death and Mitsuhide’s grand betrayal reached Toyotomi’s ear, he called a ceasefire and negotiated a peace treaty for the sole purpose of riding back to the capital to destroy Mitsuhide. Hideyoshi pushed his army tremendously to get back to Settsu in four days to face off against Mitsuhide’s troops. Hideyoshi’s honor and prowess in battle had won him the support of former Oda warriors so much so that he had a total of 20,000 men in his ranks compared to Mitsuhide’s lowly 10,000. Their forces clashed at the Battle of Yamazaki with Hideyoshi taking a decisive victory as Mitsuhide was killed fleeing the battle by a lowly bandit and having only cemented his name in history as a dishonorable coward and the thirteen- day shogunate. After the act of avenging Nobunaga, Toyotomi Hideyoshi became successor and took up the task of accomplishing Nobunaga’s goal of a united and harmonious Japan. As Hideyoshi worked swiftly to complete the campaign and unified Japan, he took care to implement many political and institutional reforms to limit attempts of insurrection against him, such as taking land resources away from those daimyo he distrusted and entrusting them to his most loyal vassals. But what set Hideyoshi apart from Nobunaga was not his accomplishment in completing Nobunaga’s grand dream of unifying Japan, but rather his ambition to expand his rule to China and Korea. Unfortunately, many of the Japanese victories on foreign soil fell flat once Hideyoshi was found dead – Japan was three centuries too early in its attempts to conquer China through capture of Korea. As Hideyoshi’s heir was his appointed successor and far too young to take leadership of the Country, Japan yet once again found itself embroiled in political and militaristic turmoil. With Hideyoshi dead, warring began once again with the Battle of Sekigahara in 1600 as his vassals were tempted by the rich possibilities of becoming shogunate, a title both Nobunaga and Hideyoshi failed to obtain during their lifetimes. Ultimately, another one of Nobunaga’s trusted aides and rival, Tokugawa Ieyasu, came out victorious by outlasting all other great warriors and legends of this period and his appointment as shogunate in 1603 officially marked the end of the bloody and ruinous Sengoku Period. United under the rule of the shogunate, Japan prospered and was peaceful as it entered the new age of Sakoku, embracing Isolationism. 

Unlike any other Japanese non-modern times, the Sengoku Period is a popular setting for countless anime, manga, and games due to the political and militaristic intricacies and intrigue that intertwine characters and their interactions with one another. For example, in Oda Nobunaga no Yabou (The Ambition of Oda Nobunaga), we see how popular settings like isekai, or traveling to alternative worlds, can create an enjoyable environment where modern-age people like us can immerse ourselves in the differences in culture and behavior present during the Sengoku Period. Of course, for those interested in getting the full experience of “conquering” of Japan from the Oda clan’s perspective, Alicesoft’s Sengoku Rance may provide an interesting outlook on the betrayal and ferocity commonplace in the day to day lives of these legends from history while exploring an action-filled RPG world.