Japanese sword in the context of "Naginata"

The National Treasure (国宝, kokuhō) refers to Tangible Cultural Properties designated by Japanese law as: “having exceptionally high value”. It applies to buildings, artworks, and crafts; selected from Important Tangible Cultural Properties by the Agency for Cultural Affairs (a special body of the Ministry of Education, Culture, Sports, Science and Technology). A Tangible Cultural Property is considered to be of historic or of artistic value, classified either as buildings and structures or as fine-arts and crafts. Each National Treasure must demonstrate outstanding workmanship, high value for world cultural history, or exceptional value for scholarship.

Approximately 20% of the National Treasures are structures such as castles, Buddhist temples, Shinto shrines, or residences. The remaining 80% include paintings, scrolls, sutras, calligraphy, sculptures in wood, bronze, lacquer or stone, as well as crafts such as pottery, lacquerware, metalworks, swords, textiles, and archaeological artifacts. The items span the period from ancient to early modern Japan before the Meiji period, including pieces of the world's oldest pottery from the Jōmon period and 19th-century documents and writings. The designation of the Akasaka Palace in 2009, the Tomioka Silk Mill in 2014, and the Kaichi School added three modern, post-Meiji Restoration National Treasures.

A blade is the sharp, cutting portion of a tool, weapon, or machine, specifically designed to puncture, chop, slice, or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are intended to cut. This includes early examples made from flaked stones like flint or obsidian, evolving through the ages into metal forms like copper, bronze, and iron, and culminating in modern versions made from steel or ceramics. Serving as one of humanity's oldest tools, blades continue to have wide-ranging applications, including in combat, cooking, and various other everyday and specialized tasks.

Blades function by concentrating force at the cutting edge. Design variations, such as serrated edges found on bread knives and saws, serve to enhance this force concentration, adapting blades for specific functions and materials. Blades thus hold a significant place both historically and in contemporary society, reflecting an evolution in material technology and utility.

A katana (刀, かたな; lit. 'one-sided blade') is a Japanese sword characterized by a curved, single-edged blade with a circular or squared guard and long grip to accommodate two hands. Developed later than the tachi, it was used by samurai in feudal Japan and worn with the edge facing upward. Since the Muromachi period, many old tachi were cut from the root and shortened, and the blade at the root was crushed and converted into a katana. The specific term for katana in Japan is uchigatana (打刀, うちがたな; lit. 'striking sword') and the term katana (刀) often refers to single-edged swords from around the world.

A Japanese kitchen knife is a type of kitchen knife used for food preparation. These knives come in many different varieties and are often made using traditional Japanese blacksmithing techniques. They can be made from stainless steel, or hagane, which is the same kind of steel used to make Japanese swords. Most knives are referred to as hōchō (Japanese: 包丁/庖丁) or the variation -bōchō in compound words (because of rendaku) but can have other names including -ba (〜刃; lit. "-blade") and -kiri (〜切り; lit. "-cutter"). There are four general categories used to distinguish the Japanese knife designs:

1. handle — Western v. Japanese construction, or a fusion of the two
2. blade grind — single bevel, kataba v. double bevel, ryōba (outside of kitchen knives, these can mean single/double edged)
3. steel — stainless v. (high) carbon
4. construction — laminated v. mono-steel

Iaidō (居合道), abbreviated iai (居合), is a Japanese martial art that emphasizes being aware and capable of quickly drawing the sword and responding to sudden attacks.

Iaido consists of four main components: the smooth, controlled movements of drawing the sword from its scabbard (or saya), striking or cutting an opponent, shaking blood from the blade, and replacing the sword in the scabbard. While beginning practitioners of iaido may start learning with a wooden sword (bokutō 木刀) depending on the teaching style of a particular instructor, most of the practitioners use a blunt-edged sword called an iaitō or mogitō. Few, more experienced, iaido practitioners use a sharp-edged sword (shinken).