Appreciating Hi and Horimono on Nihonto: Reading the Decorative Grooves and Carvings of Japanese Swords

Hi and Horimono—Two Major Elements of Blade Decoration

When you look closely at a Japanese katana blade, besides the hamon and jigane, you often see grooves or carvings on the blade. These are called "hi" and "horimono," and along with hamon and jigane, they are important objects of appreciation in sword appreciation.

Hi are grooves carved into the blade, possessing both functional aspects—such as material conservation, weight reduction, and acoustic effects—and decorative aspects that enhance the aesthetic harmony of the blade. Horimono are images with religious or mystical significance, such as dragons, kurikara, Fudō Myōō, or Sanskrit characters, carved directly into the blade.

Types and Viewing of Hi

The shape of hi varies greatly depending on the era, school, and commission. The main types can be organized as follows:

• Bouhi: The most common form, with a single narrow groove running near the mune of the blade. When a blade with bouhi is swung, it produces a "whooshing" sound, and this is said to generate a "wind-cutting sound." The thickness, depth, and positions of the starting and ending points vary according to the swordsmith.
• Futasuji-hi: A form where a thin supplementary groove (soebhi) is placed below the bouhi. This is more decorative and showcases the swordsmith's technical skill.
• Koshihi: A groove that runs only in the lower part of the blade (near the mune section). Complex grooves such as "koshihi with supplementary groove" also exist.
• Kakinagashi: A form where the groove does not extend all the way to the point but fades partway. This gives a refined impression.

When appreciating hi, by paying attention to the shape of the starting and ending points of the hi (whether "maruzume" or "tsurugi-zume," etc.), the distance from the mune, and the uniformity of depth, one can see the skill of the swordsmith.

Types of Horimono and Their Religious Background

Horimono were carved into the blade as spiritual support and wishes by samurai. The main types and their meanings are as follows:

• Kurikara: An image of a dragon coiling around the sword of Fudō Myōō, and the most widely seen horimono on Japanese swords. Also called "kurikara dragon," it is depicted with the dragon swallowing or coiling around the sword. It is believed to have the spiritual power to sever evil and ward off misfortune, and was carved as a prayer for samurai protection.
• Fudō Myōō: A wisdom king of esoteric Buddhism, depicted with an angry expression holding a sword in the right hand and a rope in the left. Fudō Myōō carvings on the blade are intended to imbue the sword itself with sacred power. Precise carvings based on mandala imagery require a high level of skill approaching that of a Buddhist sculptor.
• Bonji: Sanskrit characters representing Buddhas, bodhisattvas, or wisdom kings, carved as seeds. The seed character of Fudō Myōō, "kān," and that of Manjushri Bodhisattva, "man," are common examples. While simple in appearance, these were cherished by samurai as a symbol that elevated the spiritual power of the sword.
• Gomabashi: A rod-shaped carving modeled after a fireplace poker for homa rituals, which has connections to prayer and ritual practice. It is often carved in combination with kurikara and Fudō.

The Technique of Horimono—Swordsmiths and Horimono Specialists

Carvings on the blade were sometimes performed by the swordsmith themselves and sometimes by specialized carvers (horimono-shi). Particularly for intricate Fudō Myōō carvings or three-dimensional kurikara dragons, independent horimono specialists often took charge.

Horimono techniques are diverse, including "kata-kiri bori," "ke-bori," "maru-bori," and "taka-bori," with the quality determined by the descriptive power of the imagery, the delicacy of the lines, and the sense of three-dimensionality. When appreciating horimono, checking with a magnifying glass to see the sharpness of the carving lines, the fineness of the dragon's scales, and the finishing of the background (ji) reveals the skill level of the craftsman.

Practical Appreciation—Where to Focus

Points to consider when appreciating hi and horimono in practice are as follows:

First, regarding hi, use light reflection to check the finishing of the starting and ending points of the hi. Whether the sides of the bouhi are smoothly polished and whether the bottom maintains uniform depth are measures of technical skill. For horimono, observe the unity of the imagery and the sureness of the lines. In fine kurikara carvings, the movement of the dragon's body and the curve of the sword are organically harmonized, and while decorative, they blend seamlessly into the blade itself.

Hi and horimono are also excellent as a "gateway" to sword appreciation. Appreciating hamon and jigane requires a certain level of experience and eye, but the shape of hi and the imagery of horimono are visually easy to grasp, making them ideal subjects of appreciation as an introduction to the artistic and spiritual world of Japanese swords.

Finding Swords with Hi and Horimono—Opportunities for Purchase and Appreciation

Swords with hi and horimono are included in large numbers in the inventories of sword fairs and dealers. Swords with only bouhi are relatively common, but swords with intricate kurikara carvings or Fudō Myōō carvings are of high rarity, and tend to command higher prices compared to swords of similar condition.

For museum appreciation opportunities, the Sword Museum (Tokyo, Ryogoku) and sword-related museums throughout the country display many swords with horimono among their National Treasure and Important Cultural Property class pieces. While viewing is through glass, the depth of the hi and three-dimensionality of the horimono become visible when the lighting angle is adjusted. Participating in appreciation meetings is a valuable opportunity to hold the sword in hand and check details.

Once you become aware of the decorative elements of hi and horimono, new discoveries arise one after another from the same blade. The world of blade decoration, where functional beauty and faith converge, makes you reexperience the profound appeal of Japanese swords anew.