* Image is for illustrative purposes only.Futamata Castle
二俣城
Futamata Castle is a historic castle in Chūbu dating from the Developed by the Tokugawa in the late 1550s–1560s; fell to Takeda Shingen in 1572; site of Tokugawa Nobuyasu's forced suicide in 1579, whose lord was Tokugawa clan (early) → Takeda Shingen → Takeda Katsuyori → Tokugawa Ieyasu (site of Nobuyasu's suicide) → Horio Yoshiharu.
Overview
Futamata Castle in Hamamatsu City's Tenryū Ward is a clifftop mountain fortress above the Tenryū River, remembered above all for one of the most tragic events in Tokugawa history: the forced suicide of Tokugawa Nobuyasu, Ieyasu's eldest son, within its walls in 1579.
The castle's earlier history was shaped by the conflict between the Takeda and Tokugawa. In 1572, Takeda Shingen's "Western Advance" campaign swept through Tōtōmi Province (western Shizuoka), targeting the castle as a key Tokugawa stronghold. Unable to breach the cliff-side defenses directly, Takeda forces cut the castle's water supply by destroying the wooden mechanism of its riverside well — a technical stroke that forced surrender without direct assault. The castle fell, but was recaptured by the Tokugawa after Shingen died suddenly in 1573.
In 1579, the castle became the site of the darkest episode in Ieyasu's career. His son Tokugawa Nobuyasu (age 21), husband of Oda Nobunaga's daughter, was accused — whether by Nobunaga's instigation or Ieyasu's own calculation — and ordered to commit suicide at Futamata Castle. The full circumstances remain disputed by historians, but the event forced Ieyasu to choose between his son and his alliance with Nobunaga, a choice with profound consequences for the subsequent Tokugawa rise to power.
The castle was abandoned in the early Edo period. The surviving stone walls and earthworks on the river cliff are preserved as a National Historic Site, offering sweeping views of the Tenryū River gorge.
Connection to Swords
Futamata Castle's sword heritage is concentrated in the most intimate and philosophically charged use of the Japanese blade — the ritual suicide and beheading (kaishaku) that ended Tokugawa Nobuyasu's life within the castle walls. The tradition surrounding Nobuyasu's death includes a famous anecdote: that Hattori Hanzō, Ieyasu's celebrated retainer and sword master, was designated as kaishakunin (beheading attendant) but collapsed in tears, unable to strike down the son of his lord — a story that, whether historically precise or later embellishment, captures with startling directness the ethical contradictions embedded in the samurai's relationship to the sword. The sword as an instrument of death was not always wielded against enemies; sometimes it was the final act of loyalty to a system that demanded even the killing of the beloved. The Tōtōmi region around Futamata had its own blade-making tradition — the "Enshū kaji" (Enshū smiths), who served the Tokugawa military establishment from the Sengoku period and whose work supported the garrison culture of Ieyasu's domain before the move to Edo. The castle's position at the Tenryū River crossing also made it a conduit for iron materials flowing south from the Shinshu mountains. Takeda Shingen's technical siege — cutting the water supply through engineering rather than frontal assault — used the Tenryū River itself as a weapon, foreshadowing the siege techniques that would define the final decades of the Sengoku period. For visitors interested in the full arc of the sword's role in Japanese history, Futamata offers the most emotionally complete narrative: the sword as battle weapon, the sword as engineering tool's counterpart, and the sword as the ultimate instrument of the samurai's final obligation.
Highlights
- Futamata Castle stone walls and earthworks (National Historic Site) — clifftop ramparts above the Tenryū River gorge
- Keep platform (main bailey) — panoramic views of the Tenryū River canyon from the castle summit
- Tokugawa Nobuyasu memorial monument — the memorial to the tragic heir, erected at the castle site
- Tobayama Castle ruins (opposite hill) — the subsidiary fort built by Ieyasu to besiege Futamata
- Tenryū River rafting — the river whose water supply was weaponized by Takeda Shingen's siege engineers
- Kōmyōin temple (Nobuyasu's grave) — the family temple below the castle walls
* Opening hours and admission fees are subject to change. Please check the official website before visiting.