Iimoriyama Castle (Asuke)

History

Iimoriyamajō was first built by Asuke Shigehide in the Kamakura period as the main base of the Asuke Clan. The castle served as part of a network of forts protecting the township of Asuke, refered to as the 'seven castles of Asuke'. The seven castles of Asuke are: Iimoriyamajō, Mayumiyamajō (now commonly called Asukejō), Asuke-Shiroyamajō, Daikannonjō, Narusejō, Usukiǵaminejō and Kibyūjō. Asuke Shigenori, a later castellan, fought for Emperor Go'Daigo, but was captured and beheaded in 1331, and after that, though they continued to support the court, the clan's power waned. The Asuke Clan were pushed out of Asuke some point after 1357.

In the Sengoku period Asuke was taken over and governed by the Asuke-Suzuki Clan, founded by Suzuki Tadachika in the late 15th century. The Suzuki Clan built or rebuilt forts around Asuke, and the ruins of fortifications we see today likely date to this time at the earliest. After being attacked in Asuke by Matsudaira Kiyoyasu in 1525, the Mikawa-Suzuki pledged fealty to the ascendant Matsudaira Clan.

In 1554, the Suzuki switched their allegiance to the Imagawa Clan, but fell back in line under Matsudaira Motoyasu (Tokugawa Ieyasu) following the 1560 battle of Okehazama. Iimoriyamajō was conquered by Takeda Shingen in 1571. It was liberated in 1573 by Matsudaira Nobuyasu (Ieyasu's son), then aged 14. The Suzuki Clan were able to reclaim Asuke, and remained there until 1590.

The histories of Iimoriyamajō and Asukejō are entwined, so for further context here is a brief historical description I wrote for Asukejō:

Tradition holds that Asukejō was established by the Asuke Clan in the Kamakura period, but the veracity of this cannot be ascertained. Archaeological findings indicate the castle was built in the late 15th century, likely by Suzuki Tadachika, and was used throughout the Sengoku period. Suzuki Clan leaders after Tadachika were Shigemasa, Shigenao, Nobushige, Yasushige. Asukejō was a rare example of a mountain fort that was used continually as a residence throughout this period, and not merely as a stronghold to retreat to in times of conflict. The Suzuki were perennially under the yoke of the Matsudaira Clan (that is, the future Tokugawa), but rebelled against them several times in the Sengoku period. By the late 16th century the Suzuki were brought firmly to heel as vassals of the Matsudaira and fought for them in campaigns such as the siege of Takatenjinjō. In 1571 Takeda Shingen’s forces captured the castle and held it until 1573. In 1590, the last castellan of Asukejō, Suzuki Yasushige, relocated to the Kantō area along with his master, Tokugawa Ieyasu, following the peace and compromise between Ieyasu and Toyotomi Hideyoshi. Asukejō was thereafter abandoned. For four centuries the castle ruin was given over to nature. Excavations were carried out from 1990 to 1992 and reconstructions based on the findings of the survey followed.

Visit Notes

Iimoriyamajō is a yamajiro (mountaintop castle) ruin in Asuke Township, Toyota Municipality. I had wanted to visit this site for a long time, since first visiting Asuke in 2019. The two times I went to Asuke to see Asukejō, I wasn't able to visit Iimoriyamajō. This time I cycled the 33km from Okazaki to visit Asuke, which took only a little longer than getting the express bus, plus I got to stop for goheimochi, a local snackfood, along the way. I also had a much more extensive look around Asuke's townscape. Asuke is a beautiful mountain town.

Iimoriyamajō is accessed via Kōjakuji, a temple in the Kōran Gorge. The gorge is famous for its autumnal scenes, but I've only ever been during warmer months. There is a recreated traditional farmstead by the Tomoe River called Asuke-yashiki; it's intended as a farmer's residence rather than samurai, and it's not a historical site, but it's nonetheless nice to see. Kōjakuji, which has fine stonewalls, was the site of the kyokan (residential area for the lord) of Iimoriyamajō. The terraces behind the temple's main hall are earthworks sculpted for fortifications.

Iimoriyamajō was a fortified mountaintop. Ridges leading up the hill were terraced. Since Iimoriyamajō is especially well maintained as a park, many of these terraces, a feature of yamajiro which often get neglected, are also cleared of overgrowth, giving castle fans an unobstructed view.

Other ruins include kuruwa (baileys) and the remains of trenchwork. The main bailey is at the top of the hill, and a spacious secondary bailey sits below. There is a tertiary baily to the rear, below which is a trench ruin. The middle section of the trench appears to have been filled in as part of the mountain trail, but the cuttings into the ridge at either side are clear indications of a rear-guarding trench.

In the main bailey, which has nice views of Asuke town, there are a cluster of rocks. There is a story that the rocks were used by a giant as a foot rest or something, thus the name of the town, Asuke, being made up of the kanji for 'foot (足)' and 'assist (助)'. People hang votive tablets in the shape of a footprint or sandal on the rocks. A gazebo was constructed in the main bailey in 1989 by a bunch of Anglos from England, Scotland, Canada, America and the Bahamas, with friends from Japan.

Gallery

Castle Profile
English Name	Iimoriyama Castle (Asuke)
Japanese Name	足助飯盛山城
Alternate Names	三河飯盛山城
Founder	Asuke Shigehide
Year Founded	Kamakura Period
Castle Type	Mountaintop
Castle Condition	Ruins only
Designations	Prefectural Historic Site
Historical Period	Pre Edo Period
Features	trenches
Visitor Information
Access	Higashi-Okazaki Station on the Meitetsu-Nagoya Line; bus to Asuke (70 mins), Kōrankei-Ichinotani stop; or, Jōsui Station on the Meitetsu-Toyota Line; bus to Kōrankei (50 mins); 20 minute hike
Visitor Information	24/7 free; mountain
Time Required	60 minutes
Website	https://www.nishimikawanavi.jp/spots/detail/1471/
Location	Toyota, Aichi Prefecture
Coordinates	35° 7' 57.54" N, 137° 18' 57.42" E
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Admin
Added to Jcastle	2024
Contributor	ART
Admin Year Visited	Viewer Contributed
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