Kibiji Tour (Around Soja) ~JAN,2026~

As the new year began, my first historical tour of the year was in Okayama. While I lived in Hiroshima, I had business trips to Mizushima and Tamashima, but never had time to leisurely explore the area. This area, prominently located on the Sanyo Road and open since ancient times, has long intrigued me, so I was excited to explore the area. First, I decided to climb to a high point, standing atop the ancient fortress known as Ki-no-jo. After their defeat in the Battle of Baekgang in 663, the Yamato Imperial Court constructed several castles throughout western Japan to prepare for invasions by Silla, Goguryeo, and Tang China. This castle and Ono Castle in Dazaifu are listed among the 100 Great Castles of Japan, while Mizuki Castle in Dazaifu, Kii Castle in Saga Prefecture, and Kaneda Castle on Tsushima Island are listed among the another 100 Great Castles of Japan.

Due to the Jomon Sea Level Rise, from 5,000 years ago until the Yayoi period, the area of present-day Okayama and Kurashiki was mostly underwater, and the Kojima Peninsula was an independent island. On the other hand, the inland Soja region was land even back then, and is home to a collection of ancient ruins (huge burial mounds, shrines, and the remains of Kokubunji temples).

This region was developed early on, and rice cultivation is believed to have been introduced in the 6th century BC. Research on the Kojiki and Nihon shoki, as well as ancient tombs, has confirmed the presence of powerful chieftains comparable to those in the Izumo and Kitakyushu areas. There is a theory that Suisho, who paid tribute to the Later Han Dynasty (107), was the king of Kibi, and another theory that this area was the Kinai region of Yamataikoku, which suggests that this area was Toumakoku. Although we were unable to visit this time, Tatetsuki Tomb in Kurashiki is the largest burial mound from the Yayoi period and is dated to the end of the 2nd century, making this area one of the meccas of ancient Japanese history before the establishment of Yamato royal authority.

Tsukuriyama Kofun is the largest keyhole-shaped tumulus in the area, and is also the largest kofun in Japan (280m in length) that can be freely climbed to the top. When it was built in the first half of the 5th century, it was the largest in Japan, but later the huge kofun group of Mozu Kofun Group, including the tombs of Ojin and Nintoku, was built. It is thought that it came under the control of the Yamato court during the period of the Five Kings of Wa, and it is thought that there was a chieftain with comparable power.

The sarcophagus found at the front is made of tuff quarried from Aso, and was apparently made in the same area and transported to Kibi, giving a glimpse into the breadth of the influence of the Kibi chief.

About 2km west of the Tsukuriyama（造山） Kofun is the (another) Tsukuriyama（作山） Kofun (late 5th century), which is slightly smaller than the Tsukuriyama Kofun but is still one of the top 10 largest in Japan.

Between these two burial mounds is the Komorizuka Tomb, which dates back to the latter half of the 6th century, and from here a horizontal stone chamber of the same size as the Ishibutai in Asuka Village has been unearthed. Although the size of burial mounds began to shrink nationwide in the 6th century, this is the largest in Chugoku and Shikoku, suggesting that the Kibi chieftains continued to wield great influence.

Okayama is famous for the Momotaro, whose model is said to be Kibitsuhiko-no-Mikoto, the son of the seventh Emperor Korei, who is the enshrined deity of Kibitsuhiko Shrine and Kibitsu Shrine, the Ichinomiya shrines of Bizen and Bitchu. We visited Kibitsu Shrine, and the main hall and worship hall, which were rebuilt during the time of Ashikaga Yoshimitsu, are magnificent and designated national treasures.

Kibitsuhiko was one of the four generals appointed by Emperor Sujin to pacify the country, and was in charge of conquering Kibi. There is a legend that he defeated a demon named Ura who was based in Oninojo Castle during this time, which is connected to the story of Momotaro. In front of Kibitsu Shrine, where his headquarters was located, there is an arrow-keeping stone where Kibitsuhiko placed his bow and arrows.

Momotaro is accompanied by a dog, a monkey, and a pheasant, but the dog represents Inukaibe no Inukai Takeru no Mikoto, whose descendant is Prime Minister Inukai Tsuyoshi, who was assassinated in the May 15 Incident.

The distance between the two shrines is only about 800m in a straight line, and Kibi no Nakayama, which lies between them, was the border between Bizen and Bitchu. After climbing a steep slope in the mountains for about 15 minutes, you will find the remains of Fujiwara no Narichika. He was favored by the retired emperors Toba and Goshirakawa and rose to the position of Dainagon (chief councilor), but his plot to overthrow the Taira clan was exposed in the Shishigatani Conspiracy, and he was exiled to Bizen by Taira no Kiyomori. He apparently lived in the Korai-ji Temple in the area and died shortly thereafter, and in the Meiji era, his dilapidated memorial tower was protected and stands in the mountains.

The Ashimori River, which flows through the Soja Basin, was once the military border where the Mori and Oda clans faced off, and here stands Bitchu Takamatsu Castle, where the indomitable general Shimizu Muneharu endured a water siege. Hideyoshi built a levee in 12 days, damming the Ashimori River and turning it into a lake. Originally a strong castle that made use of low-lying marshes, the Ninomaru and Honmaru citadels that emerge above the water are not very large, and it is impressive that 5,000 soldiers were able to survive here.

When Hideyoshi heard about the Honnoji Incident, he offered to spare the lives of the castle soldiers on the condition that Muneharu commit seppuku (disembowelment) at the neighboring Myogenji Temple. After witnessing this, Hideyoshi immediately launched the Great Return from the Chugoku Era, hurrying to Kyoto to defeat Akechi Mitsuhide. Toyotomi Hidenaga is the protagonist of the historical drama, but he also participated in the war with Hideyoshi.

Ieyasu awarded the Ukita clan vassal, Hanabusa Masayuki, to this area (a vassal of the shogun with a stipend of 8,000 koku), and Myogenji Temple was protected as his family temple. Near the temple are the ruins of Goyabu, where Muneharu's vassals one after another pursued their lord and died stabbing each other to death, and beyond that we can see Mount Ishii, where Hideyoshi set up his forces.

Muneharu's descendants turned down Hideyoshi's invitation to serve the Mori clan, but the Mori clan rewarded them for their service. After the Battle of Sekigahara, the Mori clan was reduced to just under 300,000 koku in the Bungo and Choshu domains, but the family of his second son, Kageharu, was treated as a chief retainer (3,710 koku) until the end of the Edo period. And for his contributions to the restoration, the Shimizu clan was awarded the title of baron.

Shimizu Muneharu rebuilt the abandoned Bitchu Kokubunji temple in the same location, but after his death it fell into disuse again and was rebuilt again in the mid-Edo period by the monk Masutetsu. The five-story pagoda was rebuilt between the Bunsei and Tenpo eras, and stands out beautifully even from afar, blending well with the rural landscape of Bitchu.

Sesshu, famous for his ink paintings, was born here, and the Hofukuji Temple where he was placed as a child is located. It has burned down twice since Sesshu was there and has been rebuilt, but the Buddhist temple where Sesshu was tied to a pillar as a child and painted a mouse with his tears still stands today. There is also the grave of the late former Prime Minister Hashimoto Ryutaro, but I quietly left the temple without stopping by.

This was my first time at Okayama Castle (Crow Castle), but the towering black castle tower surrounding the Asahikawa River is quite charming, and together with Korakuen Garden visible on the opposite bank, it is a masterpiece of the lord Ikeda. The Okayama/Kurashiki area also has a lot to see, and although I strolled around the Soja area this time, I didn't get to see any of the early modern historical sites such as the Ukita family and the Okayama domain.

I found a delicious obanzai restaurant so I'll come again.