Nihonmatsu Castle (Kasumi-ga-jō)

The Famous Castle of Ōshū — The Pride of Kasumi-ga-jō

Nihonmatsu Castle stands in central Fukushima Prefecture in Nihonmatsu City and is affectionately known as Kasumi-ga-jō (Mist Castle). The castle's name is said to derive from the sight of approximately 2,500 cherry trees in full bloom across the castle ruins park in spring, their blossoms forming a misty veil. Today it is recognized as one of Japan's 100 Famous Castles and stands as a representative castle ruin of the Tōhoku region, welcoming many visitors.

The history of Nihonmatsu Castle traces back to the Muromachi period. Around the Ōei era (1394–1428), the Nihonmatsu clan — a branch of the Hatakeyama family and a powerful feudal lord of Ōshū — constructed a fortress atop Shirahata-yama (White Flag Mountain, 345 meters in elevation). Subsequently, the Nihonmatsu clan became embroiled in fierce struggles for supremacy with Date Masamune and was conquered in Tenshō 14 (1586) during the Battle of Nihonmatsu Castle, placing the castle under Masamune's control.

The castle's development as a kinsei (early modern) fortress began when the Niwa clan — formerly retainers of the Toyotomi — entered during the early Tokugawa era. Niwa Nagashige (1571–1637) sided with the western forces at Sekigahara but later submitted to the Tokugawa, becoming lord of Shirakawa domain. However, it was his son, Niwa Mitsushige, who entered Nihonmatsu. In Kan'ei 20 (1643), he was granted 100,700 koku and became the first daimyo of Nihonmatsu domain. Thereafter, the Niwa clan continued as lords of Nihonmatsu domain until the end of the Edo period, and Nihonmatsu Castle functioned as an important fortress of Ōshū.

Castle Development Under the Niwa Clan — The Completion of an Early Modern Fortress

Niwa Nagashige invested greatly in the castle's development, completing an extensive layout centered on the honmaru and ninomaru atop the mountain, extending down to the sanmaru and ōte-gomon (main gate) at its base. The Minowa Gate (Minowa-mon), now restored and standing, serves as the front entrance to Nihonmatsu Castle. The Minowa Gate, a stately masugata-style gate equipped with tamon-yagura (long watchtowers) on both flanks, exemplifies the character of Edo-period castle architecture.

The view from the honmaru is magnificent; with Mount Adatara's majestic form as backdrop, the Nihonmatsu castle town and the Abukuma River spread before one's gaze. Mount Adatara is the mountain celebrated in poet Takamura Kōtarō's poetry collection Chiekoshō as "the real sky," and this landscape where mountain, castle, and literature intersect symbolizes the cultural richness of Nihonmatsu.

The Boshin War and the Nihonmatsu Boys' Corps — Children Who Took Up the Sword

The most moving and most tragic event in Nihonmatsu Castle's history is the Battle of Nihonmatsu in the Boshin War of Keiō 4 (1868). After Tokugawa Yoshinobu's return of political power in 1867, battles erupted across Japan between the old shogunal forces and the new imperial government army. In Tōhoku, the Ōuetsu Reppan Dōmei (Northern Alliance) was formed, and Nihonmatsu domain joined to confront the imperial government army.

In the July battle of Meiji 1 (1868), Nihonmatsu domain faced an overwhelmingly superior imperial force with only a small garrison. What particularly stirs the hearts of people is the fierce fighting of the "Nihonmatsu Shōnentai" (Nihonmatsu Boys' Corps). With nearly all able-bodied men deployed to the front, boys aged 12 to 17 took up swords, spears, and matchlock guns to defend the castle. Among them were figures such as Kimura Jūtarō, the domain's artillery instructor, and the memory of children fighting to the last with swords in hand has been passed down to later generations as the Nihonmatsu Boys' Corps.

This event is a record of one of the final eras when the sword was wielded as a weapon in Japan, and it stands as one of the finest examples of the bushidō spirit (along with its tragic dimension) being expressed most purely in Japanese modern history, deeply inscribed in the nation's memory. The memory of boys who fought with sword in hand became the catalyst most deeply linking Nihonmatsu Castle with sword culture, and is one of the reasons TOUKENZA introduces Nihonmatsu Castle.

The Cherry Castle — Spring at Kasumi-ga-jō

Overcoming the scars of the Boshin War, Nihonmatsu has continued to develop the castle ruins as a public park since the Meiji period. Today, approximately 2,500 cherry trees are planted throughout the castle ruins park, and at the season of full bloom, the entire ruins are enveloped in a flower-mist, manifesting the "Kasumi-ga-jō" name to the present day. The "Nihonmatsu Lantern Festival" (held in October), known as one of Japan's "Three Great Lantern Festivals," continues to be passed down as a traditional event demonstrating the region's cultural vitality.

At the present Nihonmatsu Castle ruins, in addition to the restored Minowa Gate and tamon-yagura, the honmaru stone walls and tenshudai (keep platform) are well preserved, their imposing grandeur bearing witness to the scale and quality of the Edo-period fortress to this day. The Nihonmatsu City Museum, located north of the castle site, offers exhibits on the Boshin War, the Nihonmatsu Boys' Corps, and the history of the Niwa clan.

Nihonmatsu Castle and TOUKENZA

Sendai, where TOUKENZA is based, was the castle town of the Date clan — the hegemon of Tōhoku — located just north of Nihonmatsu. During the Sengoku period, fierce struggles over Nihonmatsu Castle raged between Date Masamune and the Nihonmatsu clan, with the castle's fall becoming a crucial step in Masamune's path to Ōshū supremacy. In the Boshin War, the Sendai domain, as a member of the Ōuetsu Reppan Dōmei, also fought against the imperial government army, sharing a common cause with Nihonmatsu domain.

The Sendai and Nihonmatsu domains, both samurai clans of Tōhoku, shared their destinies through many historical moments and together lived through the end of the age of swords. The year 1868, when the Nihonmatsu Boys' Corps fought with swords in hand, was only eight years before the Sword Abolishment Edict of 1876 — the very symbol of the final era when swords were wielded as weapons. In that sense, Nihonmatsu Castle, as a castle that speaks the final chapter of Japanese sword history, holds particular weight for TOUKENZA.