Chokutō (直刀) refers to a type of Japanese sword that has a straight blade without any curvature. In contrast, swords with curvature are called tantō.
In Japan, swords with straight blades were prevalent until the mid-Heian period, while blades with curvature and a defined ridge (hamon) were called tachi.
The term "tachi" is applied to straight swords, while the term "ōdachi" is used for larger swords. Shorter straight swords are referred to as yokotachi.
In the classification of Japanese art history and Japanese sword studies, these straight swords are categorized as "jokotō" or ancient swords (see also the section on Japanese swords).
History of Chokutō
Yayoi Period
The emergence of straight swords in Japan dates back to the mid-late Yayoi period, with excavations in western Japan, particularly in burial mounds, revealing their presence. Examples include the "Sokan Tō" (素環頭大刀) featuring an iron ring attached to the end of the tang (nakago) and other non-ring examples, many of which are believed to have been imported from Han Dynasty China.
Kofun Period
While iron swords began to be produced in Japan during the Kofun period, straight-edged and double-edged swords were more common in the early stages. Double-edged swords fell out of use by the end of the 5th century, and straight swords became prevalent in the later Kofun period. Straight swords from this period are referred to as "sōshoku tsurugi" or decorated swords, featuring elaborate gold, silver, and bronze fittings and decorations. Apart from their use as weapons, they were also employed for ceremonial purposes and some examples feature engraved characters on the blade.
Ezō and the Transition to Curved Blades
The indigenous inhabitants of Ezō (ancient people of Hokkaido) used straight swords known as "warabitetō," which gradually evolved into curved blades suitable for slashing attacks from horseback. This transformation occurred through the "kebukata" style, leading to the development of "musha-gusari" and eventually to the Japanese sword through the "kebukata" style and "mōsō tachi."
Asuka and Nara Periods
Straight swords with straightened blades and cut ridges have been excavated from the Asuka period, indicating that flat and ridged swords were already being produced during this time.
Kofun Period
Throughout the Kofun period, straight swords were predominantly used with both hands, featuring hilt lengths of 15 centimeters or more. However, by the latter half of the 6th century, one-handed straight swords with hilt lengths of 10 centimeters or less became the norm, and blade lengths also decreased to 75 centimeters or less. This change is believed to be due to the increase in the use of horseback riding in combat, leading to the adaptation of weapons for cavalry warfare.
Chokutō in Hokkaido
While straight swords fell out of use in Honshu, Shikoku, and Kyushu with the emergence of curved swords during the Heian period, straight wooden-handled swords persisted in Hokkaido until the 13th-14th centuries. This continued until the development of Ezo-tō and Ezo-goshirae in the 15th century.