The Shimosaka school of Province was a collective enterprise in which several smiths forged blades under the shared trademark "Shimosaka." In the earliest phase, the first-generation Yasutsugu is thought to have served as the group's central figure. Signatures occur in multiple forms -- " no Shimosaka," " Daijō Shimosaka," and " Daijō Fujiwara Shimosaka" -- and among those bearing the Daijō title, at least three contemporaneous smiths are identified: Yasutsugu, Sadakuni, and Kanenori. The has noted that the chisel movement and brush-like intent in their characters are alike or of the tendency, and their workmanship styles share common features, making it difficult at present to assign individual Shimosaka signatures to specific hands on a definitive basis.
The school's characteristic mode is a forging of mixed with , flowing overall with a tendency toward standing grain (), producing conspicuous -like effects. and are present, and the steel sometimes shows an admixture of somewhat blackish . The typically takes the form of a narrow or with a tightening and ; fine are applied, and the tends toward a (subdued) quality. Where elements appear, they manifest as shallow mixed with , with entering and and enlivening the . A further hallmark of the school is the relief carving () of "true" and other subjects executed within on both sides -- work displaying the distinctive traits of Kinai-bori ( Kinai-style carving), rendered with powerful chisel finishing.
The Shimosaka school's works span , , , and , and are consistently recognized as superior pieces within the early tradition. Their blades are valued both as accomplished examples of craftsmanship and as important reference material for understanding the formative period of the Shimosaka group before individual identities fully crystallized.