National Historic SiteKantō

八王子城

Hachioji Castle

Lord

Hōjō Ujiteru

Era

Built in the Tenshō era (1573–1590)

Designation

National Historic Site

Location

Motohachimachi 3-chome, Hachioji, Tokyo

Access

From JR/Keio 'Takao Station' North Exit, take Nishi-Tokyo Bus approx. 10 min to 'Reien-mae / Hachioji-jōseki Iriguchi'; guidance facility and御主殿 approx. 20 min walk; summit approx. 40 more min

Overview

Hachioji Castle on Castle Mountain (approx. 445 m) in western Tokyo was the largest mountain stronghold of the Later Hōjō clan, built by Hōjō Ujiteru to guard the crucial Kōshū highway approach to the Kantō. On June 23, 1590, during Toyotomi Hideyoshi's siege of Odawara, a coalition army led by Maeda Toshiie and Uesugi Kagekatsu attacked Hachioji Castle with tens of thousands of troops against a garrison of 3,000. The castle fell in hours. Women and children reportedly threw themselves into the castle stream, which ran red with blood — a tragedy still remembered in local ghost stories. A month later, Odawara fell and the Hōjō clan was extinguished. The ruins, a National Historic Site, preserve impressive stone walls and the御主殿 (lord's palace) site near the slopes of Mount Takao.

Connection to Swords

The Later Hōjō clan, Kantō's greatest Sengoku power, had deep connections to sword culture. Hachioji Castle controlled the Kōshū highway, through which Kai (Yamanashi) swords and Shinshū whetstones traveled to the Kantō. The Hōjō armed a massive military machine requiring constant supplies of high-quality swords, patronizing local smiths and sourcing blades widely. The Sagami (Kanagawa) region they dominated is the homeland of Sōshū-den — the tradition of legendary smiths Masamune, Sadamune, and Akihiro — making the Hōjō domain one of Japan's richest sword culture regions. The Hachioji Castle Ruins Guidance Facility displays materials about the castle's history and the Hōjō clan's warrior culture.

Highlights

御主殿 stone walls and gates — restored Hōjō lord's palace complex
Castle stream (site of the tragic 1590 fall)
Hiking through rich forest on the slopes of Mount Takao
Hachioji Castle Ruins Guidance Facility — history and Hōjō warrior culture
Mount Takao (walkable) — Michelin three-star sacred mountain adjacent to the ruins