* Image is for illustrative purposes only.Tanaka Castle
田中城
Tanaka Castle is a historic castle in Chūbu dating from the Built circa 1558–1570 (Eiroku era), whose lord was Takeda clan / Tokugawa Ieyasu / Honda Shigetsugu.
Overview
About the Castle
Tanaka Castle, located in Fujieda, Shizuoka Prefecture, is an exceptionally distinctive castle with a highly unique layout that has attracted the attention of castle researchers as one of the most fascinating examples in Japanese castle history. Its most distinctive feature lies in its "concentric circle" (rinkaku-shiki) layout, in which the honmaru, ninomaru, sannomaru, and outer ramparts are arranged in concentric circles, and when viewed from directly above, the entire castle formed a perfect circle—a rare and extraordinary design concept. This perfectly circular layout is called "enkaushiki" (circular style), which is extremely rare in Japan, and Tanaka Castle is known as a representative example of it (Tanaka Castle was also known by alternative names such as Kameshiro Castle and Kamekō Castle).
A Disputed Territory Between the Takeda and Tokugawa
The border region between Suruga and Tōtōmi provinces where Tanaka Castle was located was a strategic strongpoint fiercely contested between Takeda Shingen and Tokugawa Ieyasu. Tanaka Castle was a fortification developed by the Takeda clan to secure their advance route into Tōtōmi, and its importance increased during the three-way struggle among the Takeda, Imagawa, and Tokugawa from the Eiroku to Tenshō periods. Takeda Shingen actively utilized Tanaka Castle as a front-line base to strengthen his control from Suruga into Tōtōmi. After the fall of the Takeda clan in Tenshō 10 (1582), it came under the control of Tokugawa Ieyasu, and throughout the Edo period it continued to serve as a stronghold for controlling Suruga and Tōtōmi while experiencing several changes of daimyo.
Connection to Tokugawa Ieyasu's Later Years
Tanaka Castle maintained a deep connection with the later years of Tokugawa Ieyasu's life. It is recorded that in Genwa 2 (1616), Ieyasu, who was in retirement as Ōgosho at Sunpu Castle, stopped by Tanaka Castle while out hawking, and after eating sea bream tempura offered by the locals, he experienced a decline in his health. There are various theories about the veracity of this anecdote, but it is a historical fact that Ieyasu frequently visited the areas around Tanaka Castle, and the geographical proximity of Sunpu and Tanaka demonstrates Ieyasu's daily range of movement. The story that Ieyasu's health declined due to sea bream tempura is widely known as the origin of the famous popular theory of "Ieyasu died from tempura."
The Honda Clan of Tanaka Domain and Samurai Traditions
In Kyōho 15 (1730), Honda Masanori was enfeoffed in Tanaka with a fief of 40,000 koku, and thereafter the Honda clan ruled Tanaka Domain for seven generations until the Meiji Restoration. This Honda clan was descended from Honda Shigenari, brother of Honda Masanobu, a senior retainer of Tokugawa Ieyasu. It should be noted that Honda Shigetsugu (Sakazaemon), famous as one of Tokugawa Ieyasu's Mikawa hereditary retainers and called the "Oni-Sakazō," was a straightforward warrior, but he was not a lord of Tanaka Castle and belonged to a different lineage from the Honda clan of Tanaka Domain. The letter that Honda Shigetsugu is said to have written to his wife, "Ippitsu Keiō: Mind the fire. Don't make Sen cry. Fatten the horse," is famous as the shortest letter in Japan, and as a straightforward expression of affection from a blunt warrior, it continues to capture the hearts of many people today. The "Sen" (お仙) to whom this letter was written later became Honda Narushige, the first daimyo of Maruoka Domain, and in Maruoka-chō, Sakai City, Fukui Prefecture, a competition for "Japan's Shortest Letter" is still held today. This letter is widely cherished as an anecdote conveying the simple and sturdy spirit of Mikawa warriors to the present day.
The Circular Layout and Castle Remains
The concentric circular layout of Tanaka Castle is highly valued by castle researchers as demonstrating the experimental aspects of Sengoku-period castle-building technology. Currently, portions of the castle's remains have been preserved, and a castle lower residence (a relocated and reconstructed replica of the honmaru) has been established in the sannomaru remains. Additionally, the well of Tanaka Castle's honmaru (commonly known as "Japan's most circular well") is known as a rare structure with a perfectly circular cross-section that symbolizes the castle's circular layout. Tanaka Castle-related historic sites are scattered throughout Fujieda City, and traces of the castle's circular layout are said to remain in the shapes of roads and waterways. This "memory of the castle etched on the map" has become an indispensable element in historical exploration of southern Shizuoka as a unique urban planning legacy of Tanaka Castle.
Suruga's Sword Culture and Tanaka Castle
Suruga Province, where Tanaka Castle was located, was the province of Sunpu Castle, where Tokugawa Ieyasu spent his later years, and throughout the Edo period it was an important region nearly under the direct control of the shogunal house. The sword smiths of Suruga produced high-level blades under the patronage of the three major powers—the Imagawa, Takeda, and Tokugawa—and in particular during the early Edo period, together with the cultural flourishing of Sunpu, sword craftsmanship reached its heyday. The samurai of Tanaka Castle wore swords produced by sword smiths of Sunpu and sword smiths of the Tōtōmi region (around Hamamatsu), and at the crossroads of the warrior culture of Suruga and Tōtōmi in the Tōkai, they cultivated a distinctive sword culture.
Connection to Swords
Tanaka Castle's sword culture possesses multilayered characteristics unique to a castle positioned at the point of contact between two major powers: the Takeda and Tokugawa. During the era when the Takeda clan controlled Tanaka Castle, elite units of the Takeda military were garrisoned there, and the blades they carried were high-quality practical battle swords manufactured by swordsmiths of Kai Province (Yamanashi). The swords wielded by the Takeda's mounted elite—the umamawari—emphasized sharpness and strength, reflecting the sturdy style characteristic of Kai swordsmiths. After the fall of the Takeda and Ieyasu Tokugawa's takeover of Tanaka Castle, Suruga swordsmiths settled in the castle town and began producing blades to meet the demands of the Tokugawa retainer corps. It is widely known that Ieyasu was an enthusiast of sword collecting throughout his life, and traditions survive indicating that during his visits to the vicinity of Tanaka Castle, he would appreciate the works and stock of local swordsmiths and dealers. Honda Shigetsugu is known as a no-nonsense warrior, yet his practical understanding of and devotion to the sword as a samurai ran deep, and he maintained at Tanaka Castle the tradition of blades that successive generations of Mikawa warriors had cherished. The swords favored by Mikawa samurai embodied a practical and robust style that valued utility over decoration, with a tendency to prefer local blades from Mikawa and Tōtōmi over the ornate swords of Bizen and Soshu. Tanaka Castle is today preserved and open to the public as the Fujieda City Museum of Local History and Literature and the Tanaka Castle Shimoshiki (Lower Residence), with some weapons and swords associated with the castle lords on display. Furthermore, adjacent Shizuoka City houses institutions such as Kunōsan Tōshōgū (Museum) and the Shizuoka City Museum of History, which preserve swords connected to Ieyasu Tokugawa, providing an excellent environment in which to comprehensively study the sword culture of Suruga alongside Tanaka Castle. The castle's distinctive concentric design—with its beautiful curves reminiscent of the kissaki (point) of the Japanese blade—may evoke a unique resonance in the hearts of those who love sword beauty, embodying the "aesthetics of circles." A visit to Tanaka Castle affords the opportunity to experience, in the most unique form, the richness of samurai culture unfolded along the Tōkaidō, Japan's greatest trunk road.
Highlights
- Concentric circular layout (rare 'rinkaku-shiki' design visible in modern streets and waterways)
- Tanaka Castle Shimoyashiki park (reconstructed honmaru buildings)
- Japan's most circular well — perfectly round cross-section, symbolic of the castle's unique design
- Fujieda City Museum (Tanaka Castle and Suruga historical materials)
- Honda Shigetsugu heritage sites (author of 'Japan's shortest letter')
- Rengejike Park (Fujieda's premier nature park, lotus blossoms)
* Opening hours and admission fees are subject to change. Please check the official website before visiting.