Perhaps the most famous of all schools of sword making is the Bizen School (備前). Within the Bizen School (備前), the Osafune (長船) ha (group) was the most prosperous and had the greatest number of eminent smiths. This group got its name because it lived in Bizen (no) Kuni Osafune Mura (備前国長船村). The founder of this ha and its greatest smith was Mitsutada (光忠). While swords were made in Osafune (長船) from the late Heian Period to the present time, the school prospered most and reached its zenith after Mitsutada (光思) founded the true Osafune School (長船).
Mitsutada (光思) was born in the first half of the 13th century and his production period is generally said to have begun when he founded the Osafune School (長船) around Ryaku-nin (1238). He was the son of Chikatada (近忠). Swords produced by Mitsutada (光忠) and his succeeding students such as Nagamitsu (長光), Sanenaga (真長), and Kagemitsu (景光) were prized in olden times and worn by famous generals and brave warriors. There are no small number of historical facts and oral tradition related to this.
Oda Nobunaga very much admired the works of Mitsutada (光忠), and it is said that he collected twenty-five of his swords. There are many famous Mitsutada swords such as the Fukushima Mitsutada (福島光忠), which was worn by Fukushima Masanori; the Ikeda Mitsutada (池田光忠), which was originally owned by Sogo Saemon, a Daimyo of Settsu no Kuni under Ikeda; and the Shokudai Kiri Mitsutada (燭台切光忠). This sword got which got its name after it cut through a large iron candle holder (shokudai) with the stroke that Date Masamune used when he beheaded one of his pages (servants). There are similar stories and bits of lore about other famous swords by Mitsutada (光忠) and the smiths of Mitsutada’s Osafune group such as Nagamitsu (長光).
As noted, Mitsutada (光忠), one of the great sword smiths of all time, founded the Osafune School (長船), which is the largest school in the entire history of the Japanese sword. According to “Kokon Mei-zukushi (Directory of Mei of Old and New Times), he worked around Hoji (1247-1249) and Kencho (1249-1256). Since is it also commonly thought that he founded the Osafune School (長船) around Ryaku-nin (1238) and the earliest dated swords for his son, Nagamitsu (長光), start around Bunei (1264-1275), we can place his active production period between 1238 and 1260. Unfortunately, I do not know of any works by Mitsutada (光忠) with a nengo (date) that, if they existed, could shed some light on the dates of his production.
One of the most interesting points of study about the blades of Mitsutada (光忠) is the apparent difference between his signed and unsigned blades. The majority of works by Mitsutada (光忠) are attributed, ô-suriage mumei blades. Such attributed blades have a magnificent shape of the mid-Kamakura style with a sugata that is wide and sturdy with a short ikubi kissaki. They have a beautiful ji-hada that is very well worked with a hint of ji-nie thus having features in common with Kyoto swords (Yamashiro School). The majority of hamon of these mumei swords are large patterned and essentially a chôji style midare tempering. On the other hand, the signed tachi have a shape that is elegant in width and thickness, and, in comparison to the attributed, unsigned works, the hamon have a style of workmanship that is relatively moderate compared to the unsigned blades. It should be pointed out, however, that while the chôji midare hamon of the signed blades is relatively quiet compared to the unsigned ones, it is more outstanding than that of his son and student, Nagamitsu (長光).
At first blush one might think that we are dealing with two different smiths, but the question of whether the attributed, mumei blades were made by any smith other than Mitsutada (光忠) has never been a point of conjecture. Rather some of the texts put forth and interesting theory that the difference between the two types of swords resulted from the extraordinarily width and length of the former type. These swords were greatly shortened during the Tensho (1573-1592) and Keicho (1596-1615) eras with their signatures being lost, while the latter type of swords, originally made in a more normal size, had no need to be largely shortened allowing the mei to stay in the lower half of the remaining nakago. The hamon in the largely shortened swords necessarily had to be large and florid to match the dimensions of the swords.
SUGATA: Tachi are the most common. There is one ken blade but, to date, no tanto have been found. Most of his blades are o-suirage mumei. These blades are in the tachi style of the mid-Kamakura era with a wide mihaba, strong and magnificent sugata with koshi-zori, funbari, and ending in an ikubi kissaki. The signed examples are smaller in general proportion and more graceful in appearance.
JITETSU: Generally, a very fine ko-itame hada will be mixed with some mokume hada. On occasion, however, on some blades a very tight ko-mokume seems more prevalent. Fine ji-nie will be present throughout the ji and a strong midare-utsuri will stand out vividly.
HAMON: His hamon is choji based and will contain o-choji midare mixed with kawazuko, gunome, and togari-gokoro variations containing ashi and yo. It is particularly florid in the o-suriage mumei examples of his work.
BÔSHI: Midare-komi, nioi fukai with a shallow kaeri. Occasionally there is one that is ko-maru or yakizume style (no turn-back).
HORIMONO: Bo-hi seems to be common on his swords with the tip of the hi carved well up into the koshinogi. The end at the nakago seems to be flat (if the blade is ubu).
NAKAGO: On the few ubu blades the nakago appears long and has niku. The end is finished in a rather flat kurijiri. The file marks are katte-sagari.
MEI: Of the few signed examples all except one are ni-ji mei, Mitsutada (光思). There is one existing blade with a naga-mei. It is the Gomotsu tachi which belongs to the Imperial Family Collection and is signed, Bizen (no) Kuni Osafune Mitsutada (備前国 長船 光思).