On a now in Osaka, dated the eighth month of Shōhō 2 (1645), Ōmura Kaboku cut not only his signature but a small manifesto: the construction, "true fifteen-plate kabuse" (真十五枚甲伏), the proud disclaimer "I am no smith" (予非鍛冶), and a line that the blade was forged to be heard of nine hundred years hence. The man behind that inscription was Ōmori Jibuzaemon, a physician born at Anzai on the outskirts of Sunpu in Suruga, who took up the forge as an avocation alongside his medical practice. By his own account in the Hihō, his treatise on swords, he began forging in the third month of Shōhō 1 (1644) and over the forty-one years to Jōkyō 1 (1684) made about a hundred blades. He served Matsudaira Mitsunaga, lord of Takada in Echigo, by virtue of his medicine; after that house was dispossessed he became a rōnin, went up to , and entered the attendance of Tokugawa Mitsukuni of the Mito domain. His teacher is not clearly known, and his small signed corpus is prized by the published sources as much for the documentary value of its long inscriptions as for the blades themselves.
Kaboku worked in two distinct manners, and the that runs through both is the thread that ties his hand together. The first is a brilliant tradition. Over an mixed with , densely forged and carrying a standing , he tempers a large mixed with , into which and enter frequently; the is deep and the clear, and the runs slightly before turning in . The published sources liken this work to the splendid of the Ishidō current, calling it "the fine Ishidō-style workmanship" (石堂風の見事な丁子出来), and judge his masterpieces to lie among these -tradition pieces. His other manner is . There the temper is a broad or a -based large worked deep in , with thick , and , and and coursing freely through the edge.
The shifts with the manner, and reading it is the surest way into his work. In the mode the forging is a dense with , the grain tightly closed beneath the bright that rises in the old . In the mode the stands a little more openly, here mixed with moku and flowing , and carries fine together with a that enters well though subdued; on the latest of the surviving blades the steel color is described as somewhat blackish, a strong, clearly textured . His shapes are those of an early- : with , a thick and a somewhat high , the shallow and the extended. The published sources praise the proportions of the sixty-second-session blade as "robust and stalwart" (頑健で屈強), an ordinary width carried with abundant .
The surviving blades let his two registers be set against one another. The eleventh-session is the voice at its clearest, its large and over a bright judged probably his finest, the published sources calling it "likely his crowning achievement" (恐らくその白眉であろう). The nineteenth and twenty-third pieces lean to , the one a wide with and , the other a -based large in deep . The sixty-second-session , designated in 2016 and the most fully described of the four, is the strongest statement of that manner: a broad base mixed with , -like elements and shallow in a companion arrangement, and frequent, and the tempered so deeply that it becomes -like with on the reverse. The published sources read it as a work "plainly made with a keen awareness of Gō Yoshihiro" (郷義弘を強く意識して制作された), and note that he also left a broad in the manner of Shinkai. Across his he cut unusually full long inscriptions, recording the kabuse plate count on nearly every blade and styling himself at times Yasuhide, which is why his dated, self-named pieces are treated as valuable source material.
What distinguishes Kaboku is the breadth of an amateur who answered to no school line and ranged freely between and . His sets him among the Ishidō-influenced smiths of the early without binding him to them, while his work, looking past his own century to Gō, gives him an -tempered and a thick activity that few of his contemporaries pursued so deliberately. The published sources name Bandō Tarō Toden among his disciples, but his line did not carry far; he is remembered less as the head of a tradition than as a singular figure, a doctor of letters who forged a hundred blades and wrote a book about it, and whose surviving swords are read off their own long signatures rather than off any documented descent.
For the collector Kaboku is a rare and particular name rather than a famous one. He has no National Treasures and no Important Cultural Properties; his record runs through the rank, with four blades on official record, all of them and all signed. None carries a documented provenance in the surviving papers, and current holders are largely unrecorded, the blades having passed into private hands in Shizuoka, Tottori and Osaka among others. His total output was small to begin with, about a hundred swords across a working life that was never his principal occupation, and the designated pieces are held rather than traded; a signed Ōmura Kaboku comes to the open market only seldom. A privately held example is a notable thing for a collector to encounter, valued the more for the long inscriptions in which a seventeenth-century physician set down, in his own hand and his own words, exactly how and why he made the blade.