I see Ishido Kazunari as the visionary who happens to be the only person who could perceive and understand Toranaga’s treacherous schemes. Now, Shogun was set in 1600, so we don’t know much about their past conflicts. But what we do know is that the two Regents never liked each other much. Ishido lived by the books, while Toranaga was cunning and ambitious. The last Taiko, Nakamura Hidetoshi (or real-life Toyotomi Hideyoshi), also known as the “Great Unifier” of Japan, ruled the country until his death in 1598. At the moment of his demise, Yaechiyo, his only son and heir to the throne, wasn’t mature enough to rule the kingdom, which is why Hidetoshi, or Taiko, divided the power among the five Regents until his son was fit enough to rule. [Spoiler Alert] He never ruled Japan.
Ishido accused the Lord of Kanto, Toranaga, of expanding his family and, in the process, breaking the rules laid down for the Regents by the late Taiko. Here, Toranaga was pushing the boundaries by repeatedly marrying and producing more children (because they were the ones who would expand his empire). Furthermore, Toranaga deceitfully held Lady Ochiba (the fictional character) and her son Yaechiyo hostage, therefore further implying his ulterior motives to bring Japan under his absolute control. That was the reason why Ishido wanted to remove Toranaga from his post and execute him for treason. He kept Toranaga hostage in Osaka until the Regents made a decision about Toranaga’s fate, but eventually, Toranaga fled to develop a strategy.
The character of Ishido is based on the real-life samurai, Ishida Mitsunari, who was in charge of Taiko’s Western Army. Mitsunari met Hideyoshi at a very young age and rose up the ranks through his bravery, hard work, and dedication towards his Lord. It is said that Mitsunari had great calculating skills, which is why Hideyoshi made him his finance manager once he came to power. Later, he became a crucial part of Hideyoshi’s government and served his Lord until his death, which was the reason why he made him a Regent in the end. However, due to the enmity between Ishida and real-life Ieyasu, it is said that the latter spread some rumors about his character, therefore sowing the seeds of conflict. However, even in real life, it was Ieyasu who failed to comply with the rules and regulations of the Toyotomi government and was found guilty of conspiring against the legal heir, which was why the Regents decided to take action against him.
James Clavell’s book doesn’t suggest this theory, but I believe the fictional Ishido in the FX series was madly in love with Lady Ochiba. Or at least he was enamored by the woman’s beauty the moment he laid eyes upon her for the first time. If you remember, the fictional Toranaga had feelings for Lady Ochiba, too, and what’s a better fuel for the rivalry between two men than their love for the same woman?
Ishido didn’t waste time and revealed his feelings for Ochiba the moment she arrived in Osaka. But the question here is, did Ishido desire the throne as desperately as his arch-nemesis? I don’t think so. If there is anything that can be vouched for about both fictional and real-life Ishido, then it is the fact that they had flawless characters throughout their lifetime. Even if Ishido had married Lady Ochiba, he would have given his life to make Yaechiyo the rightful heir to the throne. However, the only issue here was that Ishido was too honest to understand Toranaga’s plan. It is actually the problem with honest men; they think the world plays fairly, too, but Toranaga was never honest, not even with his close allies. And even though Ishido was smart enough to understand Toranaga’s plan, he didn’t have the malice to play dirty.
It could be better understood from the fact that Ishido didn’t wish to kill Mariko and had sent his ninjas to kidnap her so as to gain back the trust of other Regents and their families, but Ishido’s plan backfired when Mariko decided to sacrifice her own life due to her own emotional conflict. After Mariko’s death, Toranaga quickly declared war on Ishido because he knew that Christian Regents wouldn’t be aiding his enemy after what happened with Mariko in Osaka. And, like always, Toranaga had studied the winds correctly. Not only the Regents but also Lady Ochiba made a secret pact with Toranaga and decided not to send Taiko’s army for Ishido’s aid in the Battle of Sekigahara (1600). In the end, Ishido was left all alone on the battlefield, betrayed by the Regents and his fiance. A similar event took place in real life when Kobayakawa Hideaki, Taiko Hideyoshi’s nephew, betrayed Ishida and joined Tokugawa Ieyasu to help him defeat his enemy. As mentioned earlier, Hideaki grew resentful against Ishida after Ieyasu spread rumors that Ishida turned Taiko against his nephew because Taiko didn’t give Hideaki control over Chikugo Province. In simple words, Hideaki had been waiting for the right moment to take revenge, and the Battle of Sekigahara happened to be his moment. In the fictional narrative, Mariko’s death and Ishido’s coldness towards her demise most likely influenced Lady Ochiba’s decision to conspire with Ishido’s arch-nemesis.
As is obvious, both the fictional and real-life Ishido lost the battle of Sekigahara. The real-life general tried to escape but was later captured by the villagers and beheaded in Kyoto. In James Clavell’s fictional book, on the other hand, Ishido was captured by Toranaga’s forces and buried to his neck until he finally took his last breath some three days later. What’s worse is the fact that Lady Ochiba made one of the worst decisions of her life by helping Toranaga in his battle against Ishido, as in the near future, it would be the same Shogun who would mercilessly kill the true heir in the Siege of Osaka that took place some sixteen years later, in 1614. Taiko’s heir became one of the biggest threats to Toranaga’s rule, which was why he would not only kill Yaechiyo but also his mother, his wife, and his infant son to end the family line once and for all. And that would mark the revival of the Shogunate in Japan.
