Iidesan, Fukushima’s Odd Border: Gods, Mountains, Lines in the Sand

Iidesan, Fukushima’s Odd Border: Gods, Mountains, Lines in the Sand

Want more UJ? Get our FREE newsletter 

Need a preview? See our archives

Iidesan, location of Fukushima's odd border
In western Fukushima Prefecture, an odd salient of territory extends, wedged between Niigata and Yamagata Prefectures. So why is it there?
A simplified illustration of the mountainous Fukushima-Yamagata-Niigata tri-point at Iidesan. Made by the author.
A simplified illustration of the mountainous Fukushima-Yamagata-Niigata tri-point at Iidesan. Made by the author.

No matter the purity of Paris in France, no matter the beauty of our country’s vistas, no matter how bustling Tokyo may be, how can I forget it among them! Ah, my hometown’s views: Bandaisan in the east, [Iidesan] in the northwest enfolded in snow. Soaring sublimely through town, the pure waters of the Shikimi River flow…

Kitakata native Ikarashi Osamu, writing in 1908

Humans make geopolitical boundaries. They set down with pen and paper that which then becomes an imagined reality, existing on top of our physical world. Some borders follow geographic features like rivers, but more often, they’re arbitrarily drawn. And consequently, they are rarely neat.

Even those borders that are seemingly “straight” lines have messy histories. The process that created the borders of modern Japanese prefectures has a similarly complex history. And in the Tohoku region, perhaps the strangest border is the tri-point between western Fukushima, southern Yamagata, and northern Niigata Prefectures. Its salient now belongs to Kitakata, a city most famous for its local variety of ramen. While Japan’s prefectures took their earliest form in 1871, the Iidesan tri-point now found in Kitakata was the object of a decades-long campaign. As a result, Fukushima’s modern form only dates to 1908.

This is a story of gods, mountains, wars, and lines in the proverbial sand. Why does Iidesan, along such an odd border, belong to Fukushima?

Between Prefectures, Regions, and Heaven and Earth

Iidesan — Mount Iide– is a block mountain. It’s mostly granite, but partly slate. Iidesan is the chief peak of the multi-peak Iide mountain range, in turn part of the Ōu Mountains. The range’s peaks vary from 1631 to 2128 meters; Iidesan itself is 2105 meters tall. With such rugged terrain, located as it is in what for many years was on the periphery of the empire nominally ruled from Kyoto, “inside but outside,” it is perhaps unsurprising that Iidesan was a holy mountain and the site of ascetic pilgrimage. Many similarly rugged places in the Ōu Mountains have been the focus of religious journeys. In a recent article, I covered the Dewa Sanzan, three mountains not far from Iidesan. Until the modern era, as with many other such sites of ascetic practice, women were prohibited from climbing the mountain.

En no Gyōja, by Hokusai.
En no Gyōja, with his oni attendants Zenki and Goki, as depicted by Katsushika Hokusai. (source)

There are different views as to who founded the mountain as an ascetic site. One has it that the legendary En no Ozunu, better known as En no Gyōja, founded it together with a monk from Tang China named Zhidao (Chidō-oshō in Japanese) in 652 CE (Hakuchi 3). By 1595 CE, it had already gone through several periods of prosperity and decline. That year, Gamō Ujisato, then the local daimyo ruling from nearby Kurokawa (later Aizu-Wakamatsu) Castle, ordered the reestablishment of the mountain as a pilgrimage site. Yūmyō, priest of nearby Renge-dera temple, took up the lord’s call. Iidesan has been open to pilgrims ever since, with a shrine at Iidesan’s peak.

The Explosion of Fukushima’s Mt Bandai

The year was 1888. On a pleasant summer day in Japan, the early-morning tranquility of rural Fukushima Prefecture was suddenly interrupted by an earth-shatte…

Watch our video on the catastrophic explosion of Fukushima’s Mt. Bandai – a mountain nearby to Iidesan that was also the subject of a mountain-worshipping religion.

Two Shrines As One

While it was once a syncretic Shinto-Buddhist shrine, today, the shrine on the peak is the inner shrine (oku no miya 奥の宮) of Iidesan-jinja. The lower shrine (fumoto no miya 麓宮) is in the valley below. It’s in what used to be Yamato, town but since 2006 has been part of Kitakata City. This two-part division of Iidesan-jinja would go on to prove central to the dispute that gave the Iidesan tri-point its twisting, narrow shape. In order to understand why it was taken away from Fukushima Prefecture to begin with, we need to backtrack to the Edo period.

The Fukushima salient that runs along Iidesan’s peak was historically part of Higashi-Kanbara County. This was one of the counties in Echigo Province. Today, most of it is still part of Niigata Prefecture. For most of the Edo period, Aizu domain controlled this county. Aizu, centered in the southwest of neighboring Mutsu Province, had its capital in what today is Aizuwakamatsu City. It was ruled by one of the Tokugawa shogun’s cousins. The shogun entrusted the Aizu daimyo with more than simply the administration of the daimyo’s own core territory. Together with the Shogunal territory in Minamiyama (mostly made up of modern Fukushima Prefecture’s Minami-Aizu County), it also administered Higashi-Kanbara County in Echigo.


While the inner shrine of Iidesan-jinja is in Higashi-Kanbara County, the lower shrine is in modern Kitakata City, in the former Ichinoki Village, which was in Mutsu Province’s Yama County. But for the entirety of its existence, this division mattered little, as both sides of the county and province line were under the rule of whoever controlled Aizu-Wakamatsu. But in 1868, all that changed.

Unlocking this article at the $3 or higher membership level (20% discount annually) will also dismiss ads, grant you access to our member-only Discord channel, and make you a valued member of the UJ community! Your membership directly supports our translator-writers.

Want more UJ? Get our FREE newsletter 

Need a preview? See our archives

Nyri Bakkalian

Dr. Nyri A. Bakkalian is an author, recovering academic, raconteur, and Your Favorite History Lesbian. Her PhD thesis focused on the Boshin War in the Tohoku region. She is the author of "Grey Dawn: A Tale of Abolition and Union" (Balance of Seven Press, 2020). She hosts Friday Night History on anchor.fm/fridaynighthistory and the secret to her success is Arabic coffee. She misses Sendai daily.

Japan in Translation

Subscribe to our free newsletter for a weekly digest of our best work across platforms (Web, Twitter, YouTube). Your support helps us spread the word about the Japan you don’t learn about in anime.

Want a preview? Read our archives

You’ll get one to two emails from us weekly. For more details, see our privacy policy