Osafune Harumitsu signed his blades 治光 and styled himself Jirobei-no-jo, and the published sources place him by name within a documented Sue-Bizen line: the son of Jirozaemon-no-jo Katsumitsu and the father of Jurozaemon-no-jo Harumitsu, with dated work surviving across the Eisho, Daiei and Kyoroku eras of the early sixteenth century. He belonged to the Osafune workshops in their late-Muromachi phase, the period the trade calls Sue-Bizen, when the smiths of the village worked in a shared idiom and signed with the day and month of their making. His own dated pieces are concrete: a katana of Daiei 5, a slender katana of Daiei 8, a broad katana of Daiei 4, a great naginata of Kyoroku 2, and a moroha-zukuri tanto of Daiei 7 made jointly with his father. Fujishiro rates him at the Jo-saku level.

His recognized hand is the waist-opened gunome of the Sue-Bizen group. Over a wide, strongly saki-zori uchigatana the published sources describe a broadly tempered gunome-midare with its bases opened, the koshi-no-hiraita pattern that gives the row its rhythm, mixed with slightly pointed elements and with faint yo appearing within the ha. On the slender Daiei 4 katana and on the joint tanto that opened pattern breaks further, the temper heads splitting to form the fukushiki midare the sources name as the structure peculiar to the group, with ko-ashi and yo and sunagashi running through. It is a quieter, more legible version of the same midare that the Sukesada masters were carrying to a brilliant pitch in the same decades, and it is the first thing by which his blades are known.

The forging is an itame hada, on the broad katana and the naginata standing in the grain with ji-nie adhering, on the finer blades a ko-itame packed tightly and thoroughly consolidated, mixed at times with ko-mokume. The naginata carries the fullest work of all, its ji-nie thick and chikei entering, the large gunome-midare richly covered with nie so that yubashiri and tobiyaki appear, sunagashi gathers in places, kinsuji enters and the mune is tempered. The boshi follows the temper: a midare-komi turning back, on the broad katana deeply with a shimaba at the point and an ichimai-like return, on the tanto in ko-maru, on the naginata with a pointed tendency. There is no utsuri in his work, and the kantei rests instead on the opened gunome, the tightly forged steel and the nie that gathers most strongly on his fullest blades.

The published sources draw more than one face within this single hand. On the broad Daiei 5 katana they read the koshi-opened gunome as abundant in variation and, with the blade's good preservation, call it 「同作中の出色の一口」[[c:1]], an especially outstanding example among the smith's works. On the slender Daiei 4 katana they find the temper of a smaller pattern than is typical for him and note that it 「応永備前風が遺存」[[c:2]], preserving something of the older Oei-Bizen manner, so that the slim, tachi-like sugata reaches back a century into the Bizen past. The Daiei 8 katana shows yet another facet, a broad suguha in which yo are engaged, its ko-itame strongly felt, which the sources call 「地刃健全な治光の佳作」[[c:3]], a fine work of Harumitsu sound in both ji and ha. The naginata of Kyoroku 2 carries his boldest intention, and the sources observe that he also made katana of broad width and emphatically flamboyant temper, so that the two together let one glimpse the aim behind his style.

Harumitsu is best understood beside his father. The joint tanto's commentary counts Katsumitsu among the most skillful Sue-Bizen masters alongside Munemitsu and Tadamitsu, and singles him out as the smith who 「互の目の中に丁子を交えて一段と華やかな出来口」[[c:4]], mixing choji into the gunome for a distinctly more florid and brilliant result than the plainer compound gunome general to the group. Harumitsu works within that broader group manner rather than at his father's most ornate pitch, but the published sources judge the great naginata, in ji and ha alike, a typical example of the output of the school, and they value the father-and-son joint signature as documentary material of its own. The same sources record that large naginata are not infrequently met with in Sue-Bizen, the famous one being the piece Katsumitsu forged with Yosaburozaemon-no-jo Sukesada for Ukita Noie, the lord of Bizen, which sets Harumitsu's own stout naginata within a recognized local type.

Harumitsu's surviving designated record is small and entirely signed, five blades among the Important Sword sessions from the 27th through the 44th, with no National Treasures among them, and a designation factor that places him in the middle ranks of Osafune rather than at its summit. None carries a recorded daimyo provenance, and only one has a holder of record, an institutional collection. The blades range across the wide uchigatana, the slender saki-zori katana that reads as a tachi, the stout great naginata and the moroha-zukuri tanto signed with his father, so that the small body of work shows the full breadth of his forms. He is the kind of named Sue-Bizen hand a collector encounters from time to time rather than rarely, the joint Katsumitsu-Harumitsu tanto the most documentarily interesting of the group and the great naginata the most striking, the published sources reserving for the best of them the phrase 「末備前中傑出の出来映え」[[c:5]], an outstanding level of workmanship among the works of Sue-Bizen.

Osafune Harumitsu signed his blades 治光 and styled himself Jirobei-no-jo, and the published sources place him by name within a documented Sue-Bizen line: the son of Jirozaemon-no-jo Katsumitsu and the father of Jurozaemon-no-jo Harumitsu, with dated work surviving across the Eisho, Daiei and Kyoroku eras of the early sixteenth century. He belonged to the Osafune workshops in their late-Muromachi phase, the period the trade calls Sue-Bizen, when the smiths of the village worked in a shared idiom and signed with the day and month of their making. His own dated pieces are concrete: a katana of Daiei 5, a slender katana of Daiei 8, a broad katana of Daiei 4, a great naginata of Kyoroku 2, and a moroha-zukuri tanto of Daiei 7 made jointly with his father. Fujishiro rates him at the Jo-saku level.

His recognized hand is the waist-opened gunome of the Sue-Bizen group. Over a wide, strongly saki-zori uchigatana the published sources describe a broadly tempered gunome-midare with its bases opened, the koshi-no-hiraita pattern that gives the row its rhythm, mixed with slightly pointed elements and with faint yo appearing within the ha. On the slender Daiei 4 katana and on the joint tanto that opened pattern breaks further, the temper heads splitting to form the fukushiki midare the sources name as the structure peculiar to the group, with ko-ashi and yo and sunagashi running through. It is a quieter, more legible version of the same midare that the Sukesada masters were carrying to a brilliant pitch in the same decades, and it is the first thing by which his blades are known.

The forging is an itame hada, on the broad katana and the naginata standing in the grain with ji-nie adhering, on the finer blades a ko-itame packed tightly and thoroughly consolidated, mixed at times with ko-mokume. The naginata carries the fullest work of all, its ji-nie thick and chikei entering, the large gunome-midare richly covered with nie so that yubashiri and tobiyaki appear, sunagashi gathers in places, kinsuji enters and the mune is tempered. The boshi follows the temper: a midare-komi turning back, on the broad katana deeply with a shimaba at the point and an ichimai-like return, on the tanto in ko-maru, on the naginata with a pointed tendency. There is no utsuri in his work, and the kantei rests instead on the opened gunome, the tightly forged steel and the nie that gathers most strongly on his fullest blades.

The published sources draw more than one face within this single hand. On the broad Daiei 5 katana they read the koshi-opened gunome as abundant in variation and, with the blade's good preservation, call it 「同作中の出色の一口」[[c:1]], an especially outstanding example among the smith's works. On the slender Daiei 4 katana they find the temper of a smaller pattern than is typical for him and note that it 「応永備前風が遺存」[[c:2]], preserving something of the older Oei-Bizen manner, so that the slim, tachi-like sugata reaches back a century into the Bizen past. The Daiei 8 katana shows yet another facet, a broad suguha in which yo are engaged, its ko-itame strongly felt, which the sources call 「地刃健全な治光の佳作」[[c:3]], a fine work of Harumitsu sound in both ji and ha. The naginata of Kyoroku 2 carries his boldest intention, and the sources observe that he also made katana of broad width and emphatically flamboyant temper, so that the two together let one glimpse the aim behind his style.

Harumitsu is best understood beside his father. The joint tanto's commentary counts Katsumitsu among the most skillful Sue-Bizen masters alongside Munemitsu and Tadamitsu, and singles him out as the smith who 「互の目の中に丁子を交えて一段と華やかな出来口」[[c:4]], mixing choji into the gunome for a distinctly more florid and brilliant result than the plainer compound gunome general to the group. Harumitsu works within that broader group manner rather than at his father's most ornate pitch, but the published sources judge the great naginata, in ji and ha alike, a typical example of the output of the school, and they value the father-and-son joint signature as documentary material of its own. The same sources record that large naginata are not infrequently met with in Sue-Bizen, the famous one being the piece Katsumitsu forged with Yosaburozaemon-no-jo Sukesada for Ukita Noie, the lord of Bizen, which sets Harumitsu's own stout naginata within a recognized local type.

Harumitsu's surviving designated record is small and entirely signed, five blades among the Important Sword sessions from the 27th through the 44th, with no National Treasures among them, and a designation factor that places him in the middle ranks of Osafune rather than at its summit. None carries a recorded daimyo provenance, and only one has a holder of record, an institutional collection. The blades range across the wide uchigatana, the slender saki-zori katana that reads as a tachi, the stout great naginata and the moroha-zukuri tanto signed with his father, so that the small body of work shows the full breadth of his forms. He is the kind of named Sue-Bizen hand a collector encounters from time to time rather than rarely, the joint Katsumitsu-Harumitsu tanto the most documentarily interesting of the group and the great naginata the most striking, the published sources reserving for the best of them the phrase 「末備前中傑出の出来映え」[[c:5]], an outstanding level of workmanship among the works of Sue-Bizen.