Kamiukokuji Temple Main Hall

Jōkokuji Temple Main Hall: Hokkaido's Oldest Surviving Temple Building

Nestled at the foot of Mount Iōzan in the historic town of Kaminokuni, Hokkaido, the Main Hall (Hondō) of Jōkokuji Temple stands as a remarkable survivor of Japan's northern frontier history. Designated as an Important Cultural Property of Japan in 1993, this 18th-century Buddhist hall holds the distinguished title of the oldest extant temple building in all of Hokkaido. Far removed from the well-known temple circuits of Kyoto and Nara, Jōkokuji offers visitors a rare opportunity to encounter centuries-old sacred architecture in a setting that speaks to the resilience and cultural ambitions of the people who shaped Japan's northernmost territories.

Historical Background

The origins of Jōkokuji Temple are deeply intertwined with the turbulent history of medieval Hokkaido — then known as Ezo-ga-shima (Ezo Island). According to tradition, the temple was founded in 1443 (Kakitsu 3) by a Shingon Buddhist monk named Shūen Ajari. This date coincides with a pivotal moment in northern Japanese history: the arrival of Andō Morisue, a powerful lord from the Tsugaru region of northern Honshu, who fled to Ezo Island after losing a military conflict with the Nanbu clan. Shingon monks and mountain ascetics are believed to have accompanied him, and Shūen is thought to have been among them.

Another historical tradition attributes the temple's founding to Matsumae Yoshihiro, the first lord of the Matsumae Domain, who established it to pray for the repose of his ancestor Takeda Nobuhiro. Takeda Nobuhiro was the warrior who crossed to Ezo Island in 1454 and later rose to prominence by suppressing the Koshamain Uprising in 1457, eventually founding the Kakizaki (later Matsumae) clan that would govern Hokkaido for centuries. Regardless of which founding narrative one follows, Jōkokuji has maintained an unbroken connection to the earliest chapters of Japanese settlement in Hokkaido.

Originally affiliated with the Shingon school of Buddhism, the temple served as the family temple of the lords of Katsuyama Castle from its third head priest onward. During the mid-Edo period, around the tenure of its tenth head priest, the temple converted to the Jōdo (Pure Land) school of Buddhism, an affiliation it maintains to this day.

Why It Was Designated an Important Cultural Property

On April 20, 1993, the Main Hall of Jōkokuji was designated as an Important Cultural Property of Japan by the Agency for Cultural Affairs. The designation recognized the building's exceptional significance on several grounds.

First and foremost, the hall is the oldest surviving temple building in Hokkaido. An ink inscription reading "Hōreki 8, Year of the Tiger" discovered on a supporting beam (shirin) of the inner sanctuary ceiling confirms a construction date of 1758, placing the building firmly in the mid-18th century. This makes it an extraordinarily rare example of Buddhist architecture from this era in Japan's northern frontier.

The hall also demonstrates the fully developed architectural form of a Jōdo sect main hall, featuring a clearly defined layout with an inner sanctuary (naijin) and an outer worship area (gejin). Of particular interest is its adaptation to Hokkaido's harsh climate: the front veranda has been incorporated into the interior of the building rather than left as an open-air corridor, a pragmatic modification designed to cope with the region's severe winters and heavy snowfall.

The building's structure — a single-story, hip-and-gable (irimoya-zukuri) construction with a one-bay worship porch (kōhai) — reflects the architectural conventions of its era while embodying the ingenuity required for construction in a remote northern setting. The combination of historical significance, architectural quality, and regional uniqueness made it a compelling candidate for national designation.

Architectural Highlights and Features

The Main Hall measures approximately 11.3 meters along its ridge (ketagyō) and 13.1 meters in depth (harima), creating a spacious interior befitting its role as the primary worship space of the temple. The roof is of the hip-and-gable (irimoya) style, now covered with iron sheeting — a practical adaptation common to historical buildings in snowy regions of northern Japan.

Inside, the hall is organized around the inner sanctuary (naijin), which houses the principal Buddhist images and altars. Buddhist altars and memorial tablet stands (ihaidan) are situated along the west side wall and the rear wall of the building, creating a richly layered sacred space. The ceiling of the inner sanctuary features the ink inscription that confirmed the building's 1758 construction date, providing an invaluable piece of documentary evidence embedded within the architecture itself.

Between 2008 and 2011, the hall underwent an extensive semi-dismantling restoration funded by the Agency for Cultural Affairs. During this meticulous process, conservators discovered additional ink inscriptions, including one on a transom post (ranmazuka) dated to 1769 (Meiwa 6). The restoration returned the inner sanctuary to its appearance as of that year — the period when the interior was most elaborately appointed. This painstaking work ensures that today's visitors experience the hall much as worshippers would have in the late 18th century.

The Setting: Mount Iōzan and Katsuyama Castle

Jōkokuji Temple occupies a historically resonant location at the base of Mount Iōzan (159 meters), a prominent hill overlooking the Sea of Japan and the town of Kaminokuni. Directly above the temple are the ruins of Katsuyama Castle (Katsuyama-date), a major medieval fortification built in the late 15th century by Takeda Nobuhiro — the very figure whose spirit the temple was founded to honor.

Katsuyama Castle served as the political, military, and commercial headquarters of the Takeda-Kakizaki clan along the Sea of Japan coast from the late 1400s through the end of the 1500s. Extensive archaeological excavations conducted over more than two decades have unearthed over 100,000 artifacts, including Chinese celadon and porcelain, Japanese Mino and Echizen ceramics, metalwork, and — significantly — more than 500 bone and antler tools associated with the Ainu people, suggesting that Japanese settlers and indigenous Ainu may have lived side by side within the castle walls.

The proximity of Jōkokuji to this nationally designated historic site creates a rich historical landscape where visitors can trace the story of Japanese settlement in Hokkaido from its earliest days.

Visitor Information and Access

Jōkokuji Temple is located in the Katsuyama district of Kaminokuni, a small coastal town in the Hiyama Subprefecture of southwestern Hokkaido. The temple sits along a scenic route that connects several of the town's most important cultural heritage sites.

The most convenient way to reach Kaminokuni is by car from Hakodate, approximately a 100-minute drive along National Route 228 following the Sea of Japan coastline. The drive itself is a pleasure, offering sweeping views of the ocean and the rugged shoreline of the Oshima Peninsula. Alternatively, bus services operated by Hakodate Bus run from Esashi to the Kaminokuni area.

As a functioning temple, Jōkokuji does not charge an admission fee, though visitors should be respectful of ongoing religious activities. The exterior and grounds may be viewed freely, while interior access may be limited depending on the season and circumstances. It is advisable to contact the Kaminokuni Board of Education (Tel: 0139-55-2230) in advance if you wish to arrange a visit to the interior.

Surrounding Attractions

Kaminokuni is a treasure trove of cultural heritage, and several significant sites lie within easy reach of Jōkokuji Temple.

• Katsuyama Castle Ruins and Guidance Facility — A nationally designated historic site located on the hillside directly above the temple. The guidance facility features a 1:200 scale model of the castle, a CG reconstruction video, and displays of excavated artifacts. Open seasonally from late April to November.
• Former Sasanami Residence (Important Cultural Property) — The oldest surviving private dwelling in Hokkaido, built in the early 19th century by a herring fishing family. The main house and storehouses are open to the public, with exhibits on local history and Enkū Buddhist sculptures. Located approximately 1 km from Jōkokuji.
• Kaminokuni Hachiman Shrine — A Hokkaido-designated Tangible Cultural Property situated adjacent to the Former Sasanami Residence. The shrine preserves scrolls by Matsumae clan lords and guardian lion-dogs carved from shakudani stone from Fukui Prefecture.
• Enkū Buddhist Sculptures — Six sculptures by the itinerant 17th-century monk-sculptor Enkū are preserved at various locations throughout Kaminokuni, including a rare standing eleven-faced Kannon figure — the only one of its kind in Hokkaido.
• Mount Iōzan — The 159-meter summit above Jōkokuji offers panoramic views of the Sea of Japan and the surrounding landscape. In June, the hillside is ablaze with wild azaleas, and the annual Iōzan Festival draws visitors from across the region.