Yamanbagiri Kunihiro: Separating Fact from Fiction in the Sword's Legend

In the winter of 2025, visitors to the Ashikaga City Museum of Art in Tochigi Prefecture had the rare opportunity to see two swords displayed side by side that had not been in the same room for centuries: the Yamanbagiri Kunihiro — an Azuchi-Momoyama period masterwork by Horikawa Kunihiro, considered the finest of his career — and the Honsakucho-gi, the Nanbokucho-period Bizen blade that Kunihiro was commissioned to copy when he made it. Both are designated Important Cultural Properties of Japan. The exhibition was made possible by a mutual loan between the Ashikaga City Cultural Foundation, which holds the Kunihiro, and the Tokugawa Museum, which holds the original. This article tells the story of the Yamanbagiri Kunihiro — the sword itself, the smith who made it, the legend attached to its name, and the extraordinary story of how it was lost, presumed destroyed, and rediscovered in the 20th century.

Horikawa Kunihiro — The Father of the Shinto Tradition

Before understanding the Yamanbagiri Kunihiro, it is necessary to understand the man who made it — because the previous version of this article contained a significant factual error that must be corrected. Horikawa Kunihiro was not a disciple of Masamune, and the Yamanbagiri Kunihiro was not made in the 13th or 14th century. Masamune was active in the early 14th century; Kunihiro was born in 1531 and died in 1614 — two and a half centuries later. They never met.

Horikawa Kunihiro (堀川国広, 1531–1614) was a swordsmith of the Azuchi-Momoyama period, regarded as the founder of the Horikawa school and revered as the "father of the Shinto tradition" — the new wave of swordsmithing that emerged after the Sengoku period's end. Born in Hyuga Province (present-day Miyazaki Prefecture) as Tanaka Kunihiro, he first served the Ito clan of Hyuga. When that clan fell in 1577, he began a period of wandering — travelling as a mountain ascetic (yamabushi), making swords wherever commissions arose.

It was during this wandering period that he made the Yamanbagiri Kunihiro. In 1590 (Tensho 18), while in Shimotsukey Province — present-day Tochigi Prefecture — Kunihiro forged the blade for Nagao Akinaga, lord of Ashikaga Castle, at what is now the site of the Ashikaga Gakko, one of Japan's oldest educational institutions. The commission was specific: to copy a Bizen Osafune Cho-gi blade (the Honsakucho-gi) that Akinaga possessed. From this nomadic period of his career, before he settled in Kyoto's Horikawa district and founded the school that would bear his name, came what is considered his greatest work.

The Blade — What the Yamanbagiri Kunihiro Actually Is

The Copy That May Have Surpassed the Original

The Yamanbagiri Kunihiro is an utsushi — a copy of an existing blade. In the nihonto tradition, copying a celebrated predecessor's work is not considered lesser than original creation. It is a specific and demanding exercise: the copier must understand the original deeply enough to reproduce its essential qualities while inevitably bringing their own technique and aesthetic to the work. The finest utsushi are not replicas. They are interpretations.

Sword researcher Homma Junji assessed the Yamanbagiri Kunihiro as follows: "It is not a mere copy — the activity of the jihada and hamon strengthens and further emphasises the Cho-gi, adding even a boldness, such that it could be said to be outstanding even among Cho-gi's works." This assessment — that the copy exceeded the original in certain qualities — places the Yamanbagiri Kunihiro in an unusual position: an utsushi that is valued not despite being a copy, but in part because of what Kunihiro brought to the act of copying.

The Name — What "Yamanbagiri" Actually Means, and Why It Is Disputed

The name Yamanbagiri (山姥切) means "mountain hag cutter" — a reference to a yamanba, the supernatural old woman of Japanese folklore who haunts mountain passes. The legend attached to the name describes a former retainer of the Hojo clan who received the sword after the Hojo's defeat in Toyotomi Hideyoshi's Odawara campaign of 1590. When this man's wife gave birth to a child that a mountain hag was devouring, he used the sword to cut down the hag — who vanished. The sword was thereafter called the Yamanbagiri.

Here is the complication: there are two swords with a claim to the Yamanbagiri name — the Kunihiro copy and the Honsakucho-gi original — and scholars disagree about which blade the legend originally belonged to. The Agency for Cultural Affairs' database states plainly that "the origin of the Yamanbagiri name is unclear." The Tokugawa Museum, which holds the Honsakucho-gi, maintains that the original blade is not the Yamanbagiri. The legend as attached to the Kunihiro copy was documented by researcher Fukue Suiken from a pressed rubbing in 1975 — which itself drew on earlier scholarship by Sato Kanzan from 1962.

This ambiguity — which blade was first called Yamanbagiri, and which inherited the name from the other — is a genuine historical puzzle that remains unresolved. It is also, for collectors who appreciate the intellectual depth of nihonto scholarship, one of the most interesting ongoing debates in the field.

From Historical Sword to Cultural Icon — The Touken Ranbu Effect

In 2015, the browser game Touken Ranbu transformed the Yamanbagiri Kunihiro from a sword known primarily to specialist scholars and nihonto collectors into one of the most recognised blades in Japan's popular culture. As one of the game's initial roster of playable characters — and one of the five swords available to players as their first choice — the Yamanbagiri Kunihiro's character design, voice, and in-game personality reached millions of players, predominantly young women, who had no prior knowledge of the blade's history.

The consequences were significant and instructive. Visitors to the Ashikaga City Museum of Art — the institution holding the blade — increased dramatically. Young visitors who had never visited a sword museum began making specific pilgrimages to see the real blade that their game character was based on. Questions about the blade's actual history — its period, its smith, its relationship to the Honsakucho-gi — began appearing on fan sites and in museum visitor books with increasing sophistication over the years, as initial enthusiasm deepened into genuine knowledge.

The Yamanbagiri Kunihiro's story is, in miniature, the story of how popular culture and serious scholarship can interact productively around Japanese swords. The game brought people to the museum. The museum gave them the history. The history sent some of them to deeper study. A decade after Touken Ranbu's launch, there are collectors and scholars who trace their interest in nihonto directly back to a game character based on this blade.

In Closing — The Copy That Became Its Own Thing

The Yamanbagiri Kunihiro began as a commission to copy someone else's work. It was made by a wandering smith who had no permanent workshop, for a patron who wanted a reproduction of a blade he admired. It was named for a legend whose details remain contested. It was presumed lost for decades. It was rediscovered and found to be extraordinary. It was designated an Important Cultural Property. It became the basis for a game character known to millions. It was reunited, in a museum exhibition, with the original it was made to copy — four and a half centuries after the copy was first forged.

Horikawa Kunihiro did not know, in 1590 in Ashikaga, that the sword he was making for Nagao Akinaga would outlast the Hojo clan, survive an earthquake, be presumed lost and then found again, and eventually be seen by museum visitors who knew it first as a game character with a self-deprecating inner monologue about being "only a copy." He knew the steel, and the model he was given, and the commission he had accepted.

What he produced was not only a copy. It was a sword that scholar Homma Junji said could be "outstanding even among Cho-gi's works." The copy became its own thing — worthy of study, worthy of designation, worthy of a museum exhibition alongside the blade it was made to imitate. That is the measure of what Horikawa Kunihiro achieved in Ashikaga in the second month of Tensho 18.