On a tanto dated the eighth month of Chokyo 2 (1488), Osafune Munemitsu forged a thick-kasane hira-zukuri with strong uchizori and a withered fukura, over a refined ko-itame with ji-nie and chikei, and tempered a bright, clear chu-suguha with kinsuji. The published sources say of it that "it is no exaggeration to call it a masterpiece among his works"[[c:1]]. Its maker, titled Sakyo-no-shin, was the second son of Rokurozaemon-no-jo Sukemitsu and the younger brother of Ukyo-no-suke Katsumitsu. The published record counts him among the representative smiths of the late-Muromachi Osafune forges collectively called Sue-Bizen. Where that school is known for a high, flamboyant temper, Munemitsu is known for the straight line.
The published sources state his individuality plainly. Examples exist of the compound gunome typical of Sue-Bizen, but beyond that he holds "an established reputation as a superior maker of suguha"[[c:2]]. His usual blade is the late-Muromachi katate-uchi uchigatana, not greatly extended in length, with sakizori and a short tang made for a one-handed draw. Over it he tempers a bright suguha, by turns slender, medium and broad. A katana dated Eisho 2 (1505) is read as showing his typical style: a broad suguha in which ashi and yo work actively, both ji and ha bright and clear. Beneath its signature a nine-character incantation is cut with the single character Katsu below it, and the published sources leave open whether this marks a joint work with Katsumitsu or simply means victory. Beside Katsumitsu the difference is one of scale. The published record notes that his hamon "is of smaller pattern, showing the manner often seen in Munemitsu"[[c:3]].
His jigane is a closely forged ko-itame with fine ji-nie and chikei, over which a midare-utsuri stands; on the more reserved pieces it appears as a bo-utsuri. A katana dated Bunmei 11 (1479) also carries the ownership inscription of Minamoto Kaga-no-kami Muneyoshi. Of it the published sources note the well-ordered jigane, the standing bo-utsuri and the slender suguha with a tight nioiguchi, which give the blade a somewhat archaic air at first sight. Of a Bunmei 13 wakizashi recorded in Honma's inventory of the Imperial collection they write that, for a Sue-Bizen work, "its utsuri is strong, a piece one is tempted to date a little earlier"[[c:4]]. On the suguha blades the boshi runs straight to a round. On both faces he cuts the devotional carvings of his time, kurikara, bonji, suken and shrine names such as Hachiman Daibosatsu and Marishiten, which the published sources treat as marks of the period and lineage rather than of this smith alone.
He also works in the flamboyant register, best seen on the wide wakizashi of the Eisho years. Over a tightly forged ko-itame with dense, fine ji-nie and a standing midare-utsuri he sets a wide temper of open-waisted gunome mixed with choji and a fukushiki-gunome-like pattern. Ashi and yo enter, small tobiyaki are scattered through it, and sunagashi and kinsuji run, the nioiguchi bright and clear. The boshi enters in midare and turns back long. The published sources call this the typical manner of the Osafune smiths of the period. They also observe that conspicuous choji in the gunome is most common in Katsumitsu among the Sue-Bizen smiths and next in Munemitsu: "choji stands out within the gunome"[[c:5]]. Because his working life was long and joint signatures survive with his nephew Jirozaemon-no-jo Katsumitsu, the published record holds that the name likely ran to a second generation, the Eisho works belonging to the second. It grants that a firm boundary between the two is hard to draw.
The published sources record that joint works of the brothers Katsumitsu and Munemitsu were prized under the name Munekatsu; the blades signed with his elder brother are recorded under Katsumitsu's name. On his own record the joint signatures run to the generations on either side of him. With his nephew Jirozaemon-no-jo Katsumitsu he signed an Eisho 5 wakizashi, and of it the sources write that the dated joint signature makes it "of great documentary value for research"[[c:6]]. A Bunmei 9 tanto signed as the second son of Sukemitsu, carved with the shrine name Tensho Daijingu, is read as "most probably meaning a joint work of father and son"[[c:7]]. On the Bunmei 13 wakizashi he signs Osafune Sakyo-no-shin, which the sources take to show that Osafune had by then passed from a place name into a surname. The published record also preserves the tradition that in Chokyo 2 he went with Katsumitsu to the shogun Ashikaga Yoshihisa's camp in Omi to forge, set up forges across Bizen and Bitchu, and fought under Akamatsu Masanori.
Munemitsu has twelve works on record: ten Juyo Token and two blades recorded in Honma's inventory of the Imperial collection. He has no National Treasure, no Important Cultural Property, no Juyo Bijutsuhin and no Tokubetsu Juyo, and Fujishiro ranks him Jo-jo saku. The variant-lacquer han-dachi koshirae of an Eisho 6 katana, a mid-Edo mounting, descends in the Date house; it was first designated Juyo Koshirae and later designated together with the blade. For a private collector the Juyo blades are the realistic encounter, the dated pieces especially valued for what they show of his long career and of the two-generation question. Signed and dated Munemitsu survive in fair number for a Sue-Bizen name, yet a sound dated example comes to market only from time to time, and a documented joint blade more rarely.