Kissaki — The Evolution of Sword Point Forms and Their Role in Appraisal

Structure and Terminology of the Kissaki

The kissaki refers to the tip portion of the blade of a Japanese sword and is made up of the following elements.

- Yokote: The horizontal ridge line marking the boundary between the kissaki and the blade body. The yokote is the "boundary line" of the kissaki; the portion beyond it constitutes the kissaki proper - Kissaki / bōshi: The hamon on the kissaki is called the "bōshi" in particular. The shape and width of the bōshi's temper are important elements in appraisal - Length of the kissaki: The length from the yokote to the tip of the blade. Kissaki are classified as "ko-kissaki" (small kissaki), "chū-kissaki" (medium kissaki), and "ō-kissaki" (large kissaki) - Shape of the kissaki: Named types include "ikubi kissaki," "kamasu kissaki," and "nobi kissaki," among others

As the tip of the sword, the kissaki is involved in both thrusting and cutting, and its shape corresponds closely to changes in fighting style.

Kissaki of the Heian Period: Establishment of the Ko-kissaki

In the Heian period (10th–12th centuries), when the Japanese sword was completed in its curved (wantō) form, the kissaki was relatively small, a shape called "ko-kissaki." Tachi of this era were specialized for slashing from horseback and were characterized by long blade length and deep curvature.

The ko-kissaki seen on tachi from the late Heian to early Kamakura period is described by modern viewers as "refined and elegant." The bōshi on the kissaki is often tempered gently and shallowly, giving it a neatness that corresponds to the supple curved beauty of the entire blade.

Kissaki of the Kamakura Period: Refinement and Diversification

The Kamakura period (12th–14th centuries) was the golden age of the Japanese sword, and the shapes of the kissaki were also refined and diversified. Early Kamakura kissaki, while continuing the Heian tradition, reflect changes in taihai (body proportions), in which the blade gained greater vigor and substantiality.

In the mid-Kamakura period, "ikubi kissaki" with broad blade width and compact kissaki appeared, and in the late Kamakura period, examples with elongated kissaki increased. After the Mongol invasions (Mōko Shūrai, 1274–1281), it is said that the form of swords was improved, leading to the imposing forms of the late Kamakura period.

Kissaki of the Nanboku-chō Period: The Age of the Ō-kissaki

The Nanboku-chō period (14th century) was one of the eras in which the shape of the Japanese sword changed most dramatically. Extremely long swords called "ōdachi" and "nodachi" were made, and the kissaki, in proportion to these, expanded into the "ō-kissaki."

The nobi kissaki and ō-kissaki of the Nanboku-chō period are distinctive shapes that, by modern sensibilities, are described as "rough and forceful." The bōshi is tempered deeply and broadly, with the hamon tempered up to near the tip of the kissaki.

The ō-kissaki of the Nanboku-chō period is a shape that foregrounds powerful practicality on the battlefield, while at the same time its distinctive aesthetic impact makes it especially popular among modern sword enthusiasts.

Kissaki of the Muromachi to Sengoku Periods: From Ōei Bizen to the Late Sengoku Period

The Muromachi to Sengoku periods (15th–16th centuries) became an era in which the practical utility of the sword was given top priority due to prolonged warfare. The Ōei Bizen of the early Muromachi period took on an elegant form modeled on Kamakura-period tachi, and large ō-kissaki like those of the Nanboku-chō period became fewer.

In the Sengoku period, mass-produced blades called "kazuuchi-mono" also circulated. In the late Sengoku period, against the backdrop of the appearance of tōsei gusoku, swords with broad blade width, thick kasane, and large kissaki also appeared, leading to the imposing forms of the Keichō shintō.

Kissaki of the Edo Period (Shintō Era): Diversification of Aesthetic Sensibility

The Edo period (shintō era, 17th–18th centuries) was an age of peace, and swords shifted their emphasis from practical use to artistic and ceremonial value. Kissaki shapes came to emphasize aesthetic proportion over combat function, and the individuality of each school and swordsmith was reflected in kissaki shape.

Tsuda Sukehiro of the Ōsaka shintō has many examples with elongated kissaki, while Edo swords around the Kanbun era show shallow curvature and compact small kissaki. The shapes of bōshi on the kissaki also diversified, and unique aesthetics developed, such as "ichimai bōshi" and "kaeri fukai bōshi."

Viewing the Kissaki in Appraisal

Observation of the kissaki is the entry point to sword appraisal, and the following points serve as basic checkpoints.

1. Size of the kissaki (determining ko-, chū-, or ō-kissaki): the first clue to the period 2. Angle and shape of the kissaki: identifying shapes such as ikubi, kamasu, and nobi 3. Width and shape of the bōshi's temper: the breadth of the temper and the shape of the bōshi tip (ko-maru, chū-maru, ō-maru, kaeri) 4. Clarity of the yokote: whether the yokote is clear depends on the condition of polishing (togi) and the state of preservation of the sword 5. Proportional relationship between the kissaki and the whole blade: balance indicates the characteristics of period and place of origin

The condition of the kissaki changes greatly with polishing (togi), so there are also cases in which excessive polishing has deformed or reduced the kissaki. Appraisers are also required to have the discernment to judge whether polishing has been excessive or insufficient.