Tachi〈Meiichi〉

A Single Character, Cut Deep: The Tachi Signed "Ichi"

On the tang of this sword, just above the upper of its two peg holes, a Kamakura-period smith cut one bold stroke with a heavy chisel: 一, the numeral one, read "ichi." That single character is the entire signature. No personal name, no province, no date. Seven centuries later, the blade it marks is a National Treasure of Japan, kept at the Sano Art Museum in Mishima, Shizuoka Prefecture.

The sword is a tachi, the long, curved blade worn edge-down by mounted warriors. Its cutting edge measures 70.9 centimeters with a curvature of 3.0 centimeters, broad at the base (3.3 centimeters) and tapering to 2.2 centimeters near the point. The official designation record places it in the mid-Kamakura period, around the mid-thirteenth century, and attributes it to the Fukuoka Ichimonji school, a celebrated group of swordsmiths working in Fukuoka in Bizen Province, present-day Setouchi City in Okayama Prefecture.

"Ichimonji" means, literally, "the character one." Smiths of this lineage often signed their work with that lone numeral rather than an individual name, which is why the maker of this particular blade has never been identified. The school's anonymity was, in a sense, its brand.

Why It Became a National Treasure

The blade was designated an Important Cultural Property on September 18, 1936, and elevated to National Treasure status on November 22, 1952, under designation number 80 in the crafts category.

Its technical qualities explain the honor. The body is forged in shinogi-zukuri form with an iori-mune (peaked back ridge). The steel shows a tight itame grain, a pattern resembling wood, with a misty reflection called midare-utsuri rising above the temper line. The hamon itself is the school's signature flourish: a flamboyant o-choji midare, large clove-shaped undulations crowding the edge, with well-developed ashi and yo (streaks and detached spots of hardened steel reaching toward the cutting edge) and fine lines of nie crystals known as kinsuji.

The official commentary makes a pointed observation: among Fukuoka Ichimonji blades of this era, work finished in nie, the larger, glittering martensite crystals visible to the naked eye, is rare. Most of the school's output leans toward nioi, a softer, mist-like effect. This blade's sparkle sets it apart even within one of the most admired schools in Japanese sword history. The same record notes that the sword survives in remarkably sound, healthy condition.

One more detail rewards a close look at the point. The boshi, the temper pattern within the tip, runs out in a yakizume finish, ending without the usual turn-back, with a light brushing effect on the reverse side. Bohi grooves are carved down both faces of the blade, stopping partway into the tang.

Nobunaga, Nagashino, and a Reward for Holding a Castle

What lifts this sword beyond connoisseurship is its provenance. According to the designation record, the warlord Oda Nobunaga presented it to Okudaira Nobumasa as a reward for his defense of Nagashino Castle.

In 1575, Nobumasa held that small castle in Mikawa Province with roughly five hundred men against a vastly larger army led by Takeda Katsuyori. His stand bought time for the combined forces of Nobunaga and Tokugawa Ieyasu to arrive, and the resulting Battle of Nagashino, fought with massed matchlock volleys, broke the Takeda cavalry and became one of the turning points of the Sengoku era. The official record dates Nobunaga's gift to Tensho 4 (1576), the year following the battle itself, though some accounts associate the presentation directly with the events of 1575.

From this episode the blade acquired its popular nickname: the Nagashino Ichimonji. Tradition also holds that Tokugawa Ieyasu, Nobumasa's other patron and soon his father-in-law, rewarded the young commander with a famous Nagamitsu blade at around the same time, a detail that hints at how highly both warlords valued the man who refused to surrender.

A sword signed with a single stroke, given by Nobunaga for a single act of endurance. The symmetry is hard to resist.

Seeing the Blade at the Sano Art Museum

The tachi is privately owned by a Shizuoka-based company and has been on deposit at the Sano Art Museum since July 2014. It is not on permanent view; the museum rotates it into its sword-themed exhibitions, which it mounts regularly, and the blade occasionally travels to loan shows at other museums. Checking the museum's exhibition schedule before visiting is essential if this sword is your goal.

When it does appear, take your time at the case. Look first at the tang for the chiseled 一, then let your eye travel up the edge and count the rhythm of the clove-shaped hamon. Under the case lighting, tilt your head slightly and the kinsuji flash like wire filaments inside the steel. The breadth of the blade near the base, with its pronounced koshi-zori curvature deepest near the hilt, gives the whole sword the planted, confident stance that thirteenth-century Bizen smiths are loved for.

The Sano Art Museum itself is a rewarding destination. Founded in 1966, it holds one of Japan's better regional sword collections, including a National Treasure naginata by Osafune Nagamitsu, and its grounds include Ryusen-en, a strolling garden fed by spring water from Mount Fuji's snowmelt.

Around Mishima

The museum sits a five-minute walk from Mishima-Tamachi Station on the Izuhakone Railway, two stops from JR Mishima Station, which is itself under an hour from Tokyo by Tokaido Shinkansen.

Mishima is a water town. Snowmelt from Fuji surfaces here in clear streams that thread between houses, and the Genbei River walking path lets you follow stepping stones right down the middle of one. Ten minutes on foot from the museum stands Mishima Taisha, the ichinomiya (first-ranked shrine) of old Izu Province, where Minamoto no Yoritomo prayed before raising his rebellion in 1180. Rakujuen, a park built around a former imperial villa beside Mishima Station, rounds out an easy day on foot. Sword pilgrims with more time can pair Mishima with the Mishima Skywalk suspension bridge for Fuji views, weather permitting.