There is a mountaintop in Mutsu Aizu.

During the Sengoku period, Moriuji Ashina, who ruled Aizu, built the castle, and Ujisato Gamou, who was deeply trusted by Masamune Date and Hideyoshi Toyotomi, who ruled Aizu, renovated it as an important strategic point. Mukaihaguroyama Castle, one of Tohoku’s largest natural fortresses, was the last stronghold of Kagekatsu Uesugi and Kanetsugu Naoe.

Ashina family crest
Aizu was enclosed for 400 years from 1189 to 1589.
At its peak, it had 720,000 koku of stone.

Age of Ashina

The Asinas of Aizu, a Miura clan from Sagami (Kanagawa Prefecture), were the retainers of Minamoto no Yoritomo, who established the Kamakura shogunate in 1192, and acquired a fief mainly in the northern part of Aizu, the breadbasket region of Aizu, through their great military success.

The 16th Moriji, who built the heyday of the Ashina clan, was the most powerful of the clan at the height of the Warring States period. He was the founder of the Reed family, and was known as the “Taishu of Aizu” with one million koku (one million koku). It was Moriji who built Mukaihaguroyama Castle over a period of eight years.
However, Morioji’s heir apparent, Moriooki, the 17th, died of illness at the young age of 29 in 1574, leaving no heir. Morioji’s wife (Date Ujime) was given as a son-in-law Nikaido Moritaka, a hostage from Sukagawa, to succeed to the Asina family, but he was slain by a vassal, and his son Kamewaka (Ou) Maru also died of illness at a young age.

Moriji was at the height of his power, but after his death in Tensho 8 at the age of 60, the family was disturbed by the subsequent issue of adoption, and in the fateful battle of Suriagehara at the foot of Mount Bandai in 1589, he was defeated by Date Masamune, putting an end to his 400-year rule of Aizu.

National Historic Site Mukaihaguroyama Castle Ruins

Mukaihaguroyama Castle, which was designated as a national historic site on August 7, 2001, is the largest castle in Tohoku. It is said to surpass even the Kasugayama Castle, which was the residence of Kenshin Uesugi, and is regarded as one of the best mountain castles in the country. Many of the remains do not appear until after the Moriji clan, and it is known that successive lords of Aizu (Date, Gamo, and Uesugi clans) repeatedly renovated the castle.

Naoe Kanetsugu of “Tenchijin” fame also had his eye on
Mukaihaguroyama Castle.

As time went by, during the reign of Uesugi Kagekatsu, Tokugawa Ieyasu seized the reins of power after the death of Toyotomi Hideyoshi, putting pressure on Kagekatsu, who had been Hideyoshi’s chief vassal. The famous “Naoe-jyo” letter was written in Aizu.

Upon hearing the news of Tokugawa Ieyasu’s attack on Aizu, Kagekatsu stopped building Kozashi Castle and began constructing a defensive fortification in the Shirakawa area. However, it is not widely known that he had already begun work on Mukaihaguroyama Castle before that. It is said that Kagekatsu spent two years renovating Mukaihaguroyama Castle as the first thing he did after entering Aizu.

It is said that Kagekatsu and Kanetsugu considered Mukaihaguroyama Castle as the last fortress against Ieyasu, and if the Sekigahara Battle of Tohoku was held in Aizu, this castle would have been the most important fortress in the area.

Related Facilities

Mukaihaguro Gallery

This facility introduces the ruins of Mukaihaguroyama Castle.
In addition to introducing and explaining the status of the survey and the status of environmental improvement with photo panels, there is also a diorama model of the ruins of the mountain castle and materials related to Mr. Ashina, including Ashina Moriuji, who built the mountain castle.

・Opening hours
Saturdays, Sundays and public holidays from April to early December
Saturdays, Sundays, and holidays
Free tour
*Subject to change.

100 Meijo stamps are placed on the right side of the gallery entrance.

Hongo Information Center

Mukaihaguroyama Castle pamphlets will be distributed, and on weekends and holidays, Mukaihaguroyama Castle sightseeing guides will be available to guide visitors to recommended spots and walking paths.
A castle seal is also available for purchase.


Mukaihaguroyama Castle Ruins Leaflet
PDF - 9.4MB

This leaflet will help you understand at a glance the relationship between Tenchijin and the ruins of Mukaihaguroyama Castle, as well as the relationship between Osamu Tezuka, the god of manga, and Aizu.

You can also obtain a copy at the Information Center. (We do not mail them).