is a name that appears in documentary sources from as early as the period and is regarded as a representative smith among the swordmakers of Oshu (Mutsu province). The lineage belongs to a branch of the Maikusa smiths, a group that continued from the early period through the and into the period. Old traditional records transmit that many swordsmiths were active in Oshu from the Nara period onward; however, among works that survive today, only those of are extant. Signed examples bearing date inscriptions from the Shochu and Kenmu eras establish a working period spanning the mid- to late era. Of particular significance is a signed "Yamato--ju Tomoto " with a date of Enkyo 4 (1311), which raises the question of whether there was migration between Oshu and Yamato, possibly through connections with Shugendo (mountain asceticism), though the matter remains unresolved.
The forging of 's works characteristically shows mixed with and , with the grain tending to stand prominently; the often appears whitish overall, and the steel surface frequently lacks pronounced (clarity). The tempering is founded upon , at times incorporating and , with adhering along a that tends toward (a subdued quality). may be observed, and at the the boundary of the hardened zone is occasionally finished with a small -otoshi. The is typically straight, turning back in , though certain works display with . Carved blade ornamentation () is common, including , , and with -men.
In both and , 's works clearly exhibit the distinctive characteristics of this tradition, and the has noted that many examples give an overall quiet impression. Among his surviving oeuvre, quality varies appreciably; certain are recognized as possessing particularly splendid workmanship and superior quality compared to the more subdued examples. One such work, held within the Imperial Household collection, is described as ranking among the finest examples of this smith's output. The preservation of signed and dated blades from the Shochu era renders them especially valuable for research on the lineage and its place among the swordmaking traditions of Oshu.