Yukimura Sanada was born in Shinano Province to Masayuki Sanada, a general of the Takeda and a minor daimyo, ruling the Sanada clan. He was the younger brother of Nobuyuki Sanada, and was thus a mere general. In 1567, Yukimura joined the Takeda Army, fighting his first battle at Mimase Pass, later befriending Sakon Shima and fighting alongside him at the Battle of Mikatagahara against the Tokugawa in 1573. He fought again at Nagashino two years later, where the Takeda clan were destroyed. This left Masayuki as an independent daimyo, and Yukimura became a general, while his brother Nobuyuki Sanada became the heir to the clan.
In 1585, Yukimura would wield his spear again when trouble came to Shinano, with the Tokugawa invading the Sanada. Yukimura called out for free warriors to assist, and Keiji Maeda, Masamune Date, Kanetsugu Naoe, and Magoichi Saika answered the call to arms. At the Battle of Ueda Castle, the "Invincible Five" single-handedly repelled the Tokugawa. As a peace treaty, the Tokugawa married Ina Sanada, the daughter of one of their loyal retainers, to Nobuyuki Sanada, which linked him to Tadakatsu Honda, the father of Ina and a brave warrior whom Yukimura had dueled with and beaten at Hitokotozaka in 1572 when he served with the Takeda Army.
By 1590, the Sanada had submitted to the Toyotomi clan, who were forcing warlords to step down one-by-one, and follow Hideyoshi Hashiba's quest for unification. Yukimura Sanada served in the Odawara Campaign, fighting at the Fall of Odawara alongside Inahime and various other warriors from across the land, including Kanetsugu Naoe and Keiji Maeda. This action brought an end to the second phase of the unification, the first being the campaigns of Nobunaga Oda. Yukimura Sanada took part in Hideyoshi's two invasions of Korea, as a reward for fighting the Kasai-Osaki Uprising of 1591.
When Hideyoshi fell ill and passed away in 1598, a succession crisis broke out. Masakage and Yukimura sided with the Toyotomi loyalists, the Western Army, while Nobuyuki and Ina sided with the Tokugawa liberals, the Eastern Army. Masakage and Yukimura attacked Numata Castle in 1600, using the excuse that they wanted to meet with Nobuyuki to see how he is. However, they abandoned the castle after hearing news that Mitsunari Ishida, the Western Army's leader, had been struck down at the Battle of Sekigahara, ending the war. In sympathy for his daughter, Tadakatsu Honda begged for Ieyasu Tokugawa to spare Yukimura, which he did to please his most loyal general. Yukimura lived in peace and exile, but returned to fighting once more in 1614, when Hideyori Toyotomi, the son of Hideyoshi, called for loyalists of the dying Toyotomi cause to fight against the Tokugawa Shogunate.
Yukimura resided in the Sanada Ward of Osaka Castle alongside his friend Kunoichi Sanada, who was a female ninja who was loyal to the Sanada clan. When the Tokugawa eventually assembled an army 164,000 strong that dwarfed the 120,000 defenders, Yukimura prepared for one last battle. He lifted his spear once more, and, despite his age, he rode out to battle; as long as he could wield a sword and ride a horse, he would go to war at the call of the Toyotomi clan.
He guarded the Sanada Ward, with help from Kai Narita and Kunoichi, the former being a former concubine of Hideyoshi. Yukimura assisted in the futile defense of the city, proving himself to be a strong warrior despite his old age. He slew many enemy warriors, including Ii Naotaka. But in the end, Yukimura knew that Osaka Castle was beyond salvation and that the most he could wish for was a warrior's death. In 1615, the final Tokugawa assault was carried out. Yukimura charged straight for Ieyasu, killing all in his path and incapacitating Masamune Date, Kanetsugu Naoe, and Hirotada Tokugawa. He reached the old Ieyasu, wounding him with a spear thrust, but was stopped by Lady Ina, who knocked him out. Wounded, perhaps mortally, Yukimura decided to retain his glory and honor by charging straight into the enemy lines alone, being slain after putting up a good fight.