Sakuma Nobumori

Sakuma Nobumori (1528-1582) was a senior elder who supported Nobunaga for many years, but his later life ended dramatically when Nobunaga confronted him with a harsh written reprimand known as the "chastisement letter" (折檻状) and exiled him to Mount Kōya. The "chastisement letter," which thoroughly criticized him for lack of military merit, remains a historically significant document illustrating the severe nature of Nobunaga's lord-retainer relationships.

Nobumori was a senior retainer of the Oda clan from Owari Province (present-day Aichi Prefecture) who served Nobunaga from youth. He participated in the Battle of Okehazama (1560) and continued to achieve distinction in battles across the country. In particular, he served as supreme commander in the prolonged campaign against the Hongan-ji, maintaining a long-term blockade of the Ishiyama Hongan-ji (near present-day Osaka Castle) for many years. This was not a simple siege but a complex campaign involving management of naval forces and supply routes as well as diplomacy with various daimyō — a burden Nobumori carried for nearly a decade.

In 1580, Nobunaga suddenly sent Nobumori and his heir Sakuma Nobuhide a nineteen-article "chastisement letter." Its contents enumerated in detail his failure to take the Hongan-ji despite ten years of blockade, his lack of strategic initiative, his failure to acquire capable retainers, and other matters, thoroughly condemning his incompetence as a retainer. The Sakuma father and son were immediately expelled and withdrew to Mount Kōya. Since Nobunaga died in the Honnō-ji Incident the following year, Nobumori never received pardon and died on Mount Kōya in 1582 at the age of 55.

In the realm of Japanese swords, Nobumori had the swordsmanship foundation of a distinguished warrior family from Owari. In the prolonged Hongan-ji campaign, the nature of siege warfare meant that commanding large armies, managing supplies, and conducting diplomacy were more important than swordsmanship, yet Nobumori himself always wore a sword as a warrior and continued to embody the spirit of bushido. The image of Nobumori spending his final years on Mount Kōya, maintaining his dignity as a warrior even after receiving Nobunaga's rebuke, symbolizes the pathos of the Sengoku warrior. As a senior retainer of the Oda clan, he was said to have been involved in the gifting of many famous swords and had deep connections with Owari swordsmiths.