The term "National Treasure" has been used in Japan to denote cultural properties since 1897, although the definition and the criteria have changed since the introduction of the term. The swords and sword mountings in the list adhere to the current definition, and have been designated national treasures according to the Law for the Protection of Cultural Properties that came into effect on June 9, 1951. The items are selected by the Ministry of Education, Culture, Sports, Science and Technology based on their "especially high historical or artistic value". The list presents 110 swords and 12 sword mountings from ancient to feudal Japan, spanning from the late Kofun to the Muromachi period. The objects are housed in Buddhist temples, Shinto shrines, museums or held privately. The Tokyo National Museum houses the largest number of these national treasures, with 20 of the 122.

During the Yayoi period from about 300 BC to 300 AD, iron tools and weapons such as knives, axes, swords or spears, were introduced to Japan from China via the Korean peninsula. Shortly after this event, Chinese, Korean, and eventually Japanese swordsmiths produced ironwork locally. Swords were forged to imitate Chinese blades: generally straight with faulty tempering. Worn slung from the waist, they were likely used as stabbing and slashing weapons. Although functionally it would generally be more accurate to define them as hacking rather than slashing weapons. Swordmaking centers developed in Yamato, San'in and Mutsu where various types of blades such as , and These of the ancient sword () period should not be confused with later of the old sword () period. The former, spelled , are Chinese style straight , while the latter, spelled , are curved blades. were produced. Flat double-edged () blades originated in the Kofun period, and around the mid-Kofun period swords evolved from thrusting to cutting weapons. Ancient swords were also religious objects according to the 8th century chronicles Nihon Shoki and Kojiki. In fact, one of the Imperial Regalia of Japan is a sword, and swords have been discovered in ancient tumuli or handed down as treasures of Shinto shrines or Buddhist temples. Few ancient blades () exist because the iron has been corroded by humidity.

The transition from straight or to deliberately curved, and much more refined Japanese swords (), occurred gradually over a long period of time, although few extant swords from the transition period exist. Dating to the 8th century, Shōsōin swords and the Kogarasu Maru show a deliberately produced curve. Yasutsuna from Hōki Province forged curved swords that are considered to be of excellent quality. Stylistic change since then is minimal, and his works are considered the beginning of the old sword () period, which existed until 1596, and produced the best-known Japanese swordsmiths. According to sources Yasutsuna may have lived in the Daidō era (806–809), around 900; or more likely, was a contemporary of Sanjō Munechika and active in the Eien era (987, 988). The change in blade shape increased with the introduction of horses (after 941) into the battlefield, from which sweeping cutting strokes with curved swords were more effective than stabbing lunges required of foot soldiers. Imparting a deliberate curve is a technological challenge requiring the reversal of natural bending that occurred when the sword edge is hammered. The development of a ridge () along the blade was essential for construction. Various military conflicts during the Heian period helped to perfect the techniques of swordsmanship, and led to the establishment of swordsmiths around the country. They settled in locations close to administrative centers, where the demand for swords was high, and in areas with easy access to ore, charcoal and water. Originally smiths did not belong to any school or tradition. Around the mid to late-Heian period distinct styles of workmanship developed in certain regional centers. The best known of these schools or traditions are the (five traditions) with each producing a distinct style of workmanship and associated with the five provinces: Yamashiro, Yamato, Bizen, Sagami/Sōshū and Mino. These five schools produced about 80% of all period swords. Each school consisted of several branches. In the late Heian period Emperor Go-Toba, a sword lover, summoned swordsmiths from the Awataguchi school of Yamashiro, the Ichimonji school of Bizen and the Aoe school of Bitchū Province to forge swords at his palace. These smiths, known as (honorable rotation smiths) are considered to have been the finest swordsmiths of their time.According to the Showa Mei Zukushi (1312–1317), one of the oldest extant lists of swordsmiths, the were Norimune, Nobufusa, Muneyoshi, Sukemune, Yukikuni, Sukenari, Sukenobu or Sukechika from Bizen province; Sadatsugu, Tsunetsugu, Tsuguie from Bitchū province and Kuniyasu, Kunitomo from Yamashiro province. Go-Toba selected from the Awataguchi, Hisakuni and Ichimonji Nobufusa to collaborate on his own tempering. Early Kamakura period had an elaborately finished tang and an elegant dignified overall shape (). daggers from the same period showed a slight outward curvature.

Around the mid-Kamakura period, the warrior class reached its peak of prosperity. Consequently, sword production was thriving in many parts of Japan. Following the Mongol invasions of 1274 and 1281, smiths aimed at producing stronger swords that would pierce the heavy armour of the invaders. To achieve this, became wider, thicker with an overall grand appearance () and a straight temper line. With the Mongol threat dissipated at the end of the Kamakura period, this trend was partially reversed, as blades grew longer with a more dignified shape than those from the mid-Kamakura period. However the so-called "unchangeable smiths", including Rai Kunitoshi, Rai Kunimitsu, Osafune Nagamitsu and Osafune Kagemitsu, continued to produce swords of the elegant style of the late Heian/early Kamakura period. These swords were particularly popular with Kyoto's aristocracy. The production of daggers increased considerably towards the late Kamakura period. Master makers include Awataguchi Yoshimitsu, Rai Kunitoshi, Shintōgo Kunimitsu, Osafune Kagemitsu, Etchū Norishige and Samonji. The appeared as a new weapon in the late Kamakura period. The confrontation between the Northern and Southern Court resulted in a 60-year-long power struggle between warrior lords known as the Nanboku-chō period and caused a tremendous demand for swords. The stylistic trends of the Kamakura period continued, and tachi were characterized by magnificent shape, growing in overall length and the length of the point (). They were generally wide and disproportionately thin. Similarly grew in size to and became known as or (extended knives). But also shorter than those of the Kamakura period were being forged. Enormous called (shouldering swords), (field swords) and with blades long were forged.Many of these were shortened into during the Momoyama period. The high demand for swords during feudal civil wars after 1467 (Sengoku period) resulted in mass production and low quality swords as swordsmiths no longer refined their own steel. There are no national treasure swords after this period.

Statistics Prefecture City National Treasures Aichi Nagoya 8 Ehime Imabari 3 Fukuoka Dazaifu 1 Fukuoka 2 Yanagawa 1 Gifu Takayama 1 Hiroshima Hatsukaichi 2 Private 5 Hyōgo Nishinomiya 2 Ibaraki Kashima 1 Tsuchiura 1 Ishikawa Kanazawa 1 Kagoshima Kagoshima 1 Kanagawa Kamakura 1 Kōchi Hidaka 1 Kyoto Kyoto 3 Nara Nara 6 Okayama Okayama 3 Private 1 Osaka Osaka 3 Private 9 Saitama Saitama 2 Shizuoka Numazu 1 Mishima 1 Private 2 Shizuoka 1 Tochigi Nikkō 4 Tokyo Private 12 Tokyo 39 Yamagata Tsuruoka 2 Yamaguchi Hōfu 1 Iwakuni 1 Period National Treasures Kofun period 1 Asuka period 2 Heian period 19 Kamakura period 86 Nanboku-chō period 13 Muromachi period 1

Usage The table's columns (except for Remarks and Design and material) are sortable pressing the arrows symbols. The following gives an overview of what is included in the table and how the sorting works. Not all tables have all of the following columns. Type/Name: type of sword or sword mounting; blades mentioned in the Kyōhō era Kyōhō Meibutsuchō as masterpieces () are mentioned by name and marked in yellow Signature: for signed swords, the signature and its reading; otherwise "unsigned" Swordsmith: name of the swordsmith who forged the blade; if applicable it includes the name of the school; the ten students of Masamune () are marked in green; the , smiths summoned to the court of Emperor Go-Toba are marked in blue Remarks: additional information such as notable owners or its curvature Date: period and year; the column entries sort by year. If the entry can only be dated to a time-period, they sort by the start year of that period Length: distance from the notch to the tip of the sword Present location: "temple/museum/shrine-name town-name prefecture-name"; column entries sort as "prefecture-name town-name temple/museum/shrine-name"

The table of sword mountings differentiates between Sword type and Mounting type; includes a column on the employed Design and material; and lists the Overall length as the mounting in addition to the sword's length.

Key #Meibutsu*One of the ten students of Masamune^One of the

Treasures

Ancient swords ()

Four ancient straight swords () and one handed down in possession of temples and shrines have been designated as National Treasure craft items.Other swords from that period have been designated as National Treasures as part of excavated sets of items in the category archaeological materials. A notable collection of 55 swords and other weapons from the 8th century have been preserved in the Shōsōin collection. Being under the supervision of the Imperial Household Agency, neither these items nor the well known Kogarasu Maru are National Treasures. Name Remarks Date Type Length Present location Double-edged blade, said to be the oldest Japanese object transmitted from generation to generation; offered to Kunitokotachi by the Kusakabe clan and worshipped as of Omura Shrine; , hilt length: , scabbard length: 0500late Kofun period chokutō Kochi Hidaka Omura ShrineOmura Shrine,Sometimes misspelled as Komura Shrine Hidaka, Kōchi or Seven Stars Sword The sword contains a gold inlay of clouds and seven stars forming the Great Bear constellation. According to a document at Shitennō-ji, this sword was owned by Prince Shōtoku. Considered to be directly imported from the Asian continent 0600Asuka period, 7th century chokutō Osaka Osaka ShintennojiShitennō-ji, Osaka The sword contains an inscription in gold inlay: which according to one theory, represents (), which is a stem-branch of the Sexagenary cycle and the author's name: . According to a document at Shitennō-ji, this sword was owned by Prince Shōtoku. Considered to be directly imported from the Asian continent 0538Asuka period chokutō Osaka Osaka ShintennojiShitennō-ji, Osaka (or ) and A chest is attached to the nomination. Legendary sword used by Emperor Jimmu to found the Japanese nation 0794early Heian period chokutō Ibaraki Kashima Kashima ShrineKashima Shrine, Kashima, Ibaraki, Ibaraki A is attached to the nomination. Handle in the shape of a Buddhist ritual implement, a pestle like weapon with three prongs (); double-edged sword for ceremonial use only 0794early Heian period tsurugi Kyoto Kyoto Kyoto National Museumcustodian: Kyoto National Museum, Kyoto, Kyoto (owner: Kongō-ji, Kawachinagano, Osaka)

Old swords () 105 swords from the period (late 10th century to 1596) including (61), (26), (11), (3), (2), (1) and (1) have been designated as national treasures. They represent works of four of the five traditions: Yamato (5), Yamashiro (19), Sōshū (19), Bizen (45); and blades from Etchū Province (3), Bitchū Province (5), Hōki Province (2) and Saikaidō (7).

Yamato Province