Kiyosu Castle

The Starting Point of a Ruler: Kiyosu Castle and Oda Nobunaga

Kiyosu Castle is a castle fortress located in Kiyosu City, Aichi Prefecture, and stands as one of Japan's most dramatic castle sites. It was from this place that Oda Nobunaga, bearing the banner "Tenka Fubu" (Rule the Realm by Force of Arms), launched his unification of Owari province and took his first steps toward the conquest of all Japan. The current keep was rebuilt at the foot of Kiyosu Bridge in 1989 (Heisei 1), and its cinnabar-red tower is beautifully reflected in the flow of the Gojō River, creating a distinctive landscape.

The history of Kiyosu Castle traces back to around Chōroku 1 (1457), when it was built as a base of the Shiba clan during the Muromachi period. It subsequently became the residence of the Oda Yamato-no-kami family (a guardian deputy), functioning as the political center of Owari Province during the Sengoku period. Nobunaga succeeded his father Nobuhide in Tenmon 20 (1551), and from Kiyosu Castle as his base, the young Nobunaga conducted his campaigns to unify Owari.

The Eve of Okehazama: From Kiyosu Castle to Victory Against Imagawa

Kiyosu Castle reached its most glorious moment in Japanese history on the morning of May 19, Eiroku 3 (1560)—the dawn of the Battle of Okehazama. A vast army said to number 25,000 men, led by Imagawa Yoshimoto, invaded Owari, capturing the Zenshōji fort and putting both Washizu and Marune strongholds in peril. Receiving this news at Kiyosu Castle, Nobunaga set out from the castle with a mere 2,000 to 3,000 men under his command.

Facing this desperate disparity in numbers, Nobunaga performed the dance of "Atsumori" and rode out to battle. This "sortie from Kiyosu Castle" is one of the most famous scenes of departure in Japanese history, and is remembered as the crystallization of Nobunaga's decisiveness, his leadership, and his fearlessness in the face of death. Kiyosu Castle is forever inscribed in Japanese history as the stage of this historical moment.

Having succeeded in his surprise attack to kill Imagawa Yoshimoto at Okehazama, Nobunaga completed the unification of Owari and, in Eiroku 10 (1567), conquered Inabayama Castle (later Gifu Castle) and moved his base from Kiyosu to Gifu. Kiyosu Castle continued to serve as the administrative and political center of Owari and functioned as a rear-support base for Nobunaga's campaigns of national unification.

The Kiyosu Council: One Night That Decided the Realm

Kiyosu Castle again took center stage in Japanese history in June of Tenshō 10 (1582). Following the Honnōji Incident on June 2, when Nobunaga was assassinated by Akechi Mitsuhide, four senior retainers—Hashiba Hideyoshi, Shibata Katsuie, Niwa Nagahide, and Ikeda Tsuneoki—convened at Kiyosu Castle to deliberate on the succession and leadership of Nobunaga's domain. This "Kiyosu Council" is one of the most important political conferences in Japanese history, and its conclusion led directly to the establishment of the Toyotomi regime.

Hideyoshi advocated for placing Nobunaga's eldest son's heir (Samboshi, later Oda Hidenobu) on the throne, while Katsuie supported Nobunaga's third son, Nobutaka. Ultimately, Hideyoshi's proposal prevailed, and Samboshi was brought to Kiyosu Castle. Having emerged victorious from this council, Hideyoshi went on to defeat Katsuie at the Battle of Shizugatake (Tenshō 11, 1583) and began his march toward the unification of Japan. Kiyosu Castle is remembered as an indispensable stage in this pivotal moment of Japanese Sengoku history.

Kiyosu and Nagoya Castle: The Castle's Dissolution

Kiyosu Castle was effectively abandoned and lost its function as a castle in Keichō 15 (1610) through the "Kiyosu Transfer" (Kiyosu-goshi) ordered by Tokugawa Ieyasu. The Kiyosu Transfer was a monumental engineering project in which the entire castle and castle town of Kiyosu were relocated wholesale to the newly constructed Nagoya Castle, with all buildings, stone, and inhabitants moved to Nagoya. As a result of this thorough relocation, almost nothing of the original Kiyosu Castle remains at the old site—neither keep nor stone walls—and the surviving ruins are extremely limited.

This history of the Kiyosu Transfer vividly demonstrates that a castle is not merely a building but a living community integrated with the townspeople of the castle town. When a castle moves, so too do the people, culture, and economy—the Kiyosu Transfer most dramatically illustrated this dynamism as a historical event. The current restored keep of Kiyosu Castle stands about 200 meters from the original site, at the foot of Kiyosu Bridge, and at the old site, only a section of earthen ramparts remains.

The Swords of the Oda Family: Nobunaga's Beloved Blades

Kiyosu Castle, as the base of Oda Nobunaga, is deeply connected to the sword culture cultivated by Nobunaga. Nobunaga was a Sengoku daimyo who actively wielded the Japanese sword not merely as a weapon but as a political and artistic symbol, and his sword collection was considered an important testament to the qualities of a ruler.

Among Nobunaga's beloved swords, particularly renowned is the "Yoshimoto Samonji." This was a celebrated blade said to have been taken from Imagawa Yoshimoto, whom Nobunaga killed at the Battle of Okehazama, and is attributed to Samonji (Chikuzen Samonji), a master swordsmith of the Nanboku-chō period who worked in Chikuzen Province (present-day Fukuoka Prefecture). Nobunaga treasured this sword greatly and gave it the name "Yoshimoto Samonji." The blade passed from Nobunaga to Hideyoshi and then to the Tokugawa family. It is now housed at Kenkun Shrine (Kyoto, Kamogyo Ward) and on deposit at the Kyoto National Museum.

Nobunaga is also famous for an anecdote involving the tantō "Yagen Tōshirō," attributed to Awataguchi Yoshimitsu, a celebrated master of the Nanboku-chō period. According to various accounts, Nobunaga either succeeded or failed (accounts differ) in testing the blade's cutting power with this tantō, and these stories convey both his obsession with celebrated swords and his forceful, bold character. Kiyosu Castle, as the point of origin of these sword stories of Nobunaga, holds special significance as a pilgrimage site for sword enthusiasts.

Kiyosu Castle and TOUKENZA

Date Masamune, who based himself at Sendai—TOUKENZA's spiritual homeland—was a general of a generation some thirty years after the era of Nobunaga at Kiyosu Castle. Masamune held Nobunaga in deep reverence and is said to have felt a strong resonance with Nobunaga's spirit of "Tenka Fubu." The famous anecdote tells that Masamune regretted throughout his life that he had not lived in time to serve under Nobunaga. Kiyosu Castle, as the youthful base of the warrior whom Masamune most admired, holds special meaning for TOUKENZA, which is connected to Masamune's legacy.

The sword that Nobunaga wore at his side as he rode from Kiyosu toward Okehazama must surely have been a masterwork wrought by a master smith. Masamune, too, was a warrior living within the same tradition as Nobunaga, and stood within the same spiritual lineage of those who revered fine swords, fine armor, and fine works of art. Kiyosu Castle, standing at the heart of the Sengoku age when the Japanese sword shone as a crystallization of authority and aesthetic beauty, is one of the places that embodies the historical depth of sword culture that TOUKENZA exists to convey.