Nobunaga's troops march at the foot of Mount FujiOil on canvas, 50×61 cm, 2012-2022, M.Tsushima
Nobunaga's territory expanded eastward. In 1582, defeating the powerful warlord, Takeda clan, Nobunaga took Kai, Shinano and Suruga Provinces, overlooked by Mount Fuji. It was the moment of his culmination.
Background
In 1582, Nobunaga ruined Takeda clan, powerful warlord having ruled Kai, Shinano and Suruga provinces. That was the pivotal moment ending 10 years of war against Takeda Clan.Nobunaga then ruled 28 provinces out of 66 provinces of Japan, establishing himself as the leading warlord to unify Japan.
After the war on Kai Province, on his way back to Azuchi, Nobunaga passed the foot of Mount Fuji.
Accounts
Ota Gyuichi(1527-1613), a samurai who served Nobunaga, writes[1]:On April 12, Nobunaga left Motosu at dawn. It was cold as midwinter. At Kaminogahara and Ideno at the foot of Mount Fuji, Nobunaga allowed all the guards troops to gallop the horse aggressively, play "okurui", He saw the Mount Fuji which was crowned with snow like a white cloud. It is really an unusually great mountain.
Nobunaga's war on Kai Province
Kai Province was ruled by the powerful warlord, Takeda clan. But after the defeat at the battle of Nagashino by Nogunaga in 1575, Takeda clan began to decline. On 25 February, 1582, Nobunaga launched the decisive campaign against Takeda clan, dispatched the army led by his son, Oda Nobutada. Nobutada conqured Takeda clan's headquarter at Kofu on 30 March, and killed Takeda family members.The war on Takeda clan was almost over when Nobunaga departed his headquarter at Azuchi on 28 March. All he was to do in the warfare was to prize his generals and to make an inspection of the acquired land.
On 11 April, Nobunaga arrived at Suwa, where he assembled his generals, saw surrendered Takeda's samurais, and re-distributed the acquired lands to them.
The Return journey from Kai Province
After the inspection Nobunaga allowed his men to go home by their own means, while he with his guards left Suwa on 24 April for the return journey to Azuchi.The return journey route was different from the onward one: he went southward to take the route along the Pacific coast; on the way he saw Mount Fuji. On 4 May, he traveled at Ideno (in today's Fujinomiya), the western foot of Mt. Fuji, where he played a game called okurui which means "Madness".
So what is okurui?
Ota Guichi, who served Nobunaga, writes in the biography of Nobunaga, Shincho Koki[1], the okurui three times. The first one was held on 3 May 1579, during the military campaign against Mori clan, at Furuikeda where Nobunaga divided his guards to two groups; one mounted and the other on foot. The mounted guards rushed into the foot soldiers. Nobunaga joined the foot soldiers to block the horses. High rank generals, together with the soldiers, enjoyed the game.
The game of okurui, he played again at the foot of the Mount Fuji, might have been just a horseplay, but possibly was a training Nobunaga invented. It was an early style of gamification, by which, players enjoy the game to develop what was essential in a actual combat: tactical maneuvers, teamworks, as well as physical and mental strength. Playing such a game might alleviate the foot soldiers' fear of enemy cavalry charge.
So, why did Nobunaga, in the game of okurui, make a combat between mounted and foot soldiers? Why did he join the foot soldiers?
Takeda was good at manueuvering cavalry. They made groups of dozens of mounted soldiers to assault enemies. So, what Nobunaga had to do was to develop tactics to defend against the Takeda cavalry charge. He found the solution: it was not to use his own cavalry, but to deploy foot soldiers armed with arquebuses defended by palisades. That led to his decisive victory in the Battle of Nagashino in 1575.
How Nobunaga came up with the defensive tactics is uncertain. Perhaps, wargames like okurui he played might have provided inspiration. What is certain is that he was a man of ingenuity. The game of okurui was not a mad invention but one of innovations he made to strengthen his military power to the extent that his troops overwhelmed their enemies one after another, making the rapid expansion of his land, made him the ruler of Japan, supreme as Mount Fuji reigns.