The shape of the Japanese sword
Hira zukuri: A blade with no shinogi or yokote, almost flat on both sides. This typology first appeared in tachi produced in the Jokoto times. Starting from the Heian period (806-) tanto and ko wakizashi are always hira zukuri.
Kiriha zukuri: A line, essentially equivalent to shinogi, which runs close to the hasaki; the shinogiji is quite large. This sugata apparently evolved from hira zukuri and, except for late imitations, is found only in blades made in the Jokoto.
Katakiriha zukuri: One side is hira zukuri or shinogi zukuri (see below), while the other is kiriha zukuri. This sugata originates around the end of the Kamakura period (1288-1334). It was particularly fashionable at the beginning of the Edo period (1596-1643) and later at the end of it (1781-1867).
Moroha zukuri: Double hasaki blade where, unlike the ken, each side is different. This blade, which may be curved, is generally seen to be produced after the middle of the Muromachi period (c. 1467).
Shinogi zukuri: Blades with the shinogi rather close to the mune, where yokote and sori are present. Produced after the Heian period (c. 987) they are also known as hon zukuri.
Shobu zukuri: Similar to shinogi zukuri but without the yokote. The sugata is sharp and resembles an iris leaf. Common in time and wakizashi of the Muromachi period.
Kissaki moroha zukuri: The kissaki is sharpened on both sides while the rest of the blade is sharpened differently. The style originates from the end of the Nara period (708-781) and was also imitated in more recent times. The famous “Kogarasumaru” (family treasure of the Heike, the greatest warrior family of the Heian period) has this sugata. It has a light sori and the iori is only sharpened along the top half of the blade. Swords of this type are also known as kogarasu maru zukuri, due to this particular blade.
Kanmuri otoshi zukuri: The lower half of the blade is a normal shinogi zukuri, but the shinogiji is cut diagonally, making this blade similar to shobu zukuri sugata. It is often seen produced by the swordsmen of the province of Yamato, and related schools, starting from the Kamakura period (after 1182).
Uno kubi zukuri: Literally “cormorant neck” The blade u no kubi zukuri is similar to the kanmuri otoshi zukuri, except for the shinogiji which is inclined only centrally, while the lower part of the kissaki is regular. This sugata sometimes has yokote.
Osoraku zukuri: "Osoraku" means "maybe". This rare sugata has a very large kissaki, wider than the lower portion of the blade, and is only seen in wakizashi and wakizashi. The sugata was created by Shimada Sukemune, who engraved the word "osoraku" in Japanese characters on one of its blades, which is said to have belonged to Katagiri Katsumoto, a famous general of the Sengoku period (1467-1568).
