The Rise and Fall of the Kai Genji and Takeda Clans: From Nirasaki to Kofu and Enzan (OCT, 2026)

I had booked accommodation in Nara with the intention of visiting Asuka, which had just been designated a World Heritage Site, but due to various circumstances, I had to cancel. However, I couldn't just sit around under such clear skies, so I headed to the Kofu Basin. This year I've been visiting places associated with the Satake clan, such as Akita and Hitachiota, so I thought I'd check out the ancestral sites of the related Takeda clan as well. In Ichikawamisato town, located at the confluence of the Kamanashi River and Fuefuki River at the southern end of the basin, there is the site of Minamoto no Yoshikiyo's residence, and a monument inscribed by Sanjo Sanetomi, the "Monument to the Former Sites of the Kai Genji," stands there.

The Kai Minamoto clan begins with Minamoto (Shinra Saburo) Yoshimitsu, who distinguished himself by supporting his elder brother Yoshiie during the Later Three Years' War. He held positions such as Hitachi no Suke and Kai no Kami, driving a wedge of the (Kawachi) Minamoto clan into the Kanto region. Yoshimitsu acquired territories through marriage alliances with the Hitachi Taira clan, and his eldest son, Yoshikiyo, was granted Takeda-go in Naka District and took the name Takeda Kanja. His eldest son, Yoshinari, inherited Satake-go in Naka District, and his descendants took the name Satake. Yoshikiyo was later reprimanded by the imperial court for a boundary dispute in his territory and was exiled with his sons to Ichikawa-sho in Kai Province, which is considered the beginning of the Kai Minamoto clan (Tensho 1, 1131).

Yoshikiyo, his eldest son Kiyomitsu, and their descendants scattered throughout the basin and settled there, but it was Nobuyoshi who inherited the Takeda surname, which originated in Hitachi. Nobuyoshi came of age at the Takeda Hachiman Shrine in Nirasaki and became the head of the Kai Minamoto clan. This shrine was founded in the early Heian period (822), and it is likely that Hachiman-sama (Emperor Ojin), the guardian deity of the Minamoto clan, was already enshrined there. The imposing stone torii gate at the entrance has an indescribable presence and is said to date back to the Muromachi period.

The main hall, which is designated as an Important Cultural Property, was built by Nobutora and Shingen, and it survived Nobunaga's invasion.

Nobuyoshi built Hakusan Castle behind the shrine and made it his base. The castle area is surrounded by a tall electric fence to protect against bears, making it difficult to enter and exit, which is a headache for mountain castle enthusiasts. More than 400 years later, under strong pressure from Nobunaga, Katsuyori built Shinpu Castle on the opposite bank of the Kamanashi River, 4 to 5 km away from here. The Takeda clan began in Nirasaki and ended in Nirasaki.

Nobuyoshi also restored the nearby Ganshoji Temple and made it his family temple. The wooden statue of the Amida Triad, commissioned in Kyoto, survived multiple fires, including those caused by Nobunaga's army, and is designated as an Important Cultural Property.

The tombstone is estimated to be from the Kamakura period, but if it is from the early Kamakura period, it would be a five-tiered pagoda built shortly after his death. Nobuyoshi, who raised an army at the behest of Prince Mochihito, was one of the key figures in the establishment of Minamoto no Yoritomo's shogunate, such as launching a surprise attack on Taira no Koremori's army at the Battle of Fujikawa and driving them away. However, he did not necessarily gain Yoritomo's trust and was rather viewed with suspicion.

The southeastern area of the Kofu Basin, along the Chuo Expressway, is lined with the ruins of the Kai provincial government and ancient burial mounds, creating an area that evokes a sense of antiquity. The Tsutsujigasaki Mansion, which served as the base for Nobutora and Shingen, and Kofu Castle, built after the fall of the Takeda clan, are located in the northern part of the basin, making it fascinating to consider how the political center shifted over time. Currently, the Chuo Main Line runs along the northern edge, the expressway runs along the southern edge, and the Koshu Kaido road crosses the middle of the basin, following the Kamanashi River towards Suwa. I stopped by the Ishibashi Hachiman Shrine, founded by Yoshimitsu and located along the expressway, and paid my respects at the main hall built by Shingen.

The neighborhood is home to a cluster of ancient burial mounds, including the Kai Choshizuka Kofun, the largest keyhole-shaped burial mound in the Kanto region, and a large park has been developed that includes the prefectural archaeological museum. The Choshizuka Kofun (169m in length), dating to the latter half of the 4th century, is a result of the Yamato Kingdom's unification efforts and is roughly the same size as the Asamayama Kofun (172m in length) in Takasaki City from the same period. In the 5th century, even larger burial mounds such as the Ota Tenjinyama Kofun (Ota City, 210m in length) and the Funazukayama Kofun (Ishioka City, 186m in length) appeared, suggesting that there was a powerful chieftain representing the eastern provinces in Kai who contributed to the unification of Yamato.

The excavated triangular-rimmed bronze mirror depicting divine beasts and horses in a chariot was cast using the same mold as the one found at the Bizen Kurumazuka Kofun (Okayama City). This suggests that the chieftain of Kai Province was a powerful figure of equal standing to the chieftain of Kibi Province.

I've covered quite a few historical sites related to the Takeda clan in previous articles, but this time I decided to visit the Shioyama area. This town, now known as Koshu City, merged with Katsunuma and other areas during the Heisei-era municipal mergers. The local Sugata Tenjin Shrine houses the Tatenashi armor, one of the famous Takeda family treasures known as "Mihata Tatenashi." It was passed down from Minamoto no Tameyoshi to Yoshitomo, and I can't help but be moved that this Heian period armor has been preserved along with books and oral histories and designated as a national treasure.

I missed the opportunity because it was going to be open to the public in just five days. I think it would be better to have it carefully preserved at the National Museum, but I suppose it's a valuable tourist resource for Shioyama.

I came across a temple associated with Higuchi Ichiyo in an unexpected place. The nearby Otofuji no Sato is where Ichiyo's parents' family home was located, and a literary monument stands on the temple grounds. Her portrait appeared on the 5,000 yen banknote for 20 years, starting in 2004. Due to measures against counterfeiting, banknotes will likely be changed at a fairly rapid pace from now on, but the culture of keeping a portrait of an unforgettable historical figure in one's wallet may soon disappear. In remembrance of her, who died prematurely at the age of 24, let's occasionally pick up one of her novels, "Takekurabe" or "Nigorie."

The usual route back to Tokyo is via Otsuki and Uenohara, then onto the expressway. However, from Shioyama, there are two routes: one that goes to Ome via National Route 411, which runs alongside the Daibosatsu Pass, and another that continues further north towards Chichibu. Since the mountain roads become dangerous after dark, I decided to stop by Unpoji Temple, located at an altitude of 940m, before heading to the Katsunuma Interchange. Many of the battle flags that Takeda Katsuyori's retainers brought with them during his escape are stored here, but the temple's treasure hall is by reservation only, so I was unable to visit. 

Katsuyori had received his principal wife (Keirin-in) from Hojo Ujiyasu, but Ujimasa broke his alliance with Katsuyori by not supporting Kagetora (Ujiyasu's son) in the Otate Rebellion (a succession dispute for Uesugi Kenshin) which occurred three years before the fall of the Takeda clan. It is a mystery what Ujimasa would have done if Katsuyori had been able to retreat to Musashi, but considering the situation of directly bordering Nobunaga's territory, sheltering Katsuyori and his son may have been an option. The steep Daibosatsu Pass is 1897m above sea level, the season is late March, and there were just over 80 days left until the Honnoji Incident.