Introduction

Horimono (彫物) refers to decorative and symbolic engravings carved into the blade of a Japanese sword (nihontō, 日本刀). These carvings serve both aesthetic and spiritual purposes, often reflecting Buddhist, Shinto, or warrior-related iconography. Some horimono are purely ornamental, while others are believed to imbue the blade with protection, blessings, or martial symbolism.

Skilled artisans, known as horimono-shi (彫物師, engravers), use fine chisels and polishing tools to carve intricate designs onto the shinogi-ji (鎬地, the flat surface of the blade) or along the hiraji (平地, body of the blade). These engravings can be simple grooves or elaborate depictions of deities, dragons, or sutras.

This guide explores the types, history, and functions of horimono, along with a comprehensive list of traditional engraving styles.

The Function and Purpose of Horimono

While primarily decorative, horimono can also serve functional and spiritual roles:

1. Symbolic and Spiritual Protection
   • Many horimono depict Buddhist deities, Sanskrit inscriptions, and sacred symbols believed to ward off evil and bless the warrior.
   • Samurai often carried swords with engravings of Fudō Myō-ō (不動明王, the Immovable Wisdom King) for protection in battle.
2. Personalization and Artistic Expression
   • Some horimono were custom-made for samurai, reflecting their beliefs, family crest (kamon, 家紋), or philosophical outlook.
   • The level of detail in horimono often signified the status and wealth of the owner.
3. Blade Reinforcement and Structural Benefits
   • Certain horimono styles, such as bohi (棒樋, fullers or grooves), reduce the weight of the blade while maintaining strength and balance.
   • Grooves can also help with fluid drainage, historically believed to prevent sticking when cutting through flesh.
4. Aesthetic Enhancement
   • Masterfully engraved horimono enhance the sword’s visual appeal, making each blade a unique work of art.
   • Swordsmiths sometimes collaborated with horimono-shi to harmonize the carving with the sword’s natural hada (grain pattern) and hamon (temper line).

Types of Horimono (Engravings on Japanese Swords)

Horimono can be categorized into simple geometric carvings (bohi and grooves) and complex artistic depictions (mon and figures).

I. Grooves and Functional Engravings (Bohi, 樋)

These carvings are designed to reduce weight, reinforce the blade, or improve fluid drainage.

1. Bohi (棒樋) – “Straight Groove”
   • A single, narrow groove running along the blade’s shinogi-ji or hiraji.
   • Reduces blade weight without compromising strength.
2. Futasuji-bi (二筋樋) – “Double Groove”
   • Two parallel grooves carved into the blade.
   • Offers additional weight reduction and balance enhancement.
3. Shobu-bi (勝負樋) – “Asymmetrical Groove”
   • A long groove paired with a shorter one that ends before reaching the tip.
   • Found on some tachi and naginata, aiding in blade flexibility and maneuverability.
4. Soe-bi (添樋) – “Supplementary Groove”
   • A thin, secondary groove running alongside the main bohi.
5. Naginata-hi (薙刀樋) – “Naginata Fuller”
   • A special groove design found on naginata and nagamaki, often with a hooked end near the tang.
6. Koshi-bi (腰樋) – “Short Groove”
   • A shorter groove positioned toward the base of the blade, commonly found in older tachi.
7. Tsure-bi (連樋) – “Connected Grooves”
   • Multiple grooves running together along the length of the blade.

II. Religious and Symbolic Engravings

These carvings depict deities, prayers, Sanskrit inscriptions, and mythical figures, often serving as protective charms.

8. Bonji (梵字) – “Sanskrit Characters”
   • Esoteric Buddhist symbols representing deities or sacred words.
   • Common examples include:
     • Fudō Myō-ō (不動明王) – Guardian deity of warriors.
     • Jizō Bosatsu (地蔵菩薩) – Protector of souls and travelers.
9. Fudō-Myō-ō (不動明王) – “Immovable Wisdom King”
   • A fierce Buddhist deity, often depicted with a sword and flames.
   • Symbolizes unwavering determination and protection from evil.
10. Ryū (龍) – “Dragon”

• A Japanese or Chinese-style dragon, often depicted coiling along the blade.
• Represents power, strength, and wisdom.

11. Kurikara (倶利伽羅) – “Flaming Sword of Fudō Myō-ō”

• A sword entwined with a dragon, representing divine power and purification.

12. Gomabashi (護摩箸) – “Ritual Fire Sticks”

• Two parallel vertical carvings resembling Buddhist prayer sticks.
• Symbolic of prayers for divine protection.

13. Suken (素剣) – “Straight Sword”

• A simple engraving of a straight sword or dagger, often symbolizing divine justice.

14. Kenmaki-ryū (剣巻龍) – “Sword and Coiling Dragon”

• A dragon wrapped around a stylized sword, blending warrior and mystical symbolism.

15. Hōken (宝剣) – “Sacred Treasure Sword”

• Represents one of the Three Imperial Regalia of Japan, associated with divine authority.