The school began with a single domain commission. In Keicho 1 (1596) the Nabeshima of ordered Hashimoto Shinzaemon, the smith who would sign , up to Kyoto with the carver Munenaga; there he entered the gate of Myoju and studied forging while Munenaga learned the chisel. The two returned to the province in Keicho 3 (1598), and settled in the castle town below Saga, where under the domain's patronage the line grew into the dominant sword-making house of Kyushu. His own work runs from Keicho 5 (1600) to his death in 'ei 9 (1632); in Genna 10 (1624) he received the court title Daijo, changed his name to Tadahiro, and shifted his clan name from Minamoto to Fujiwara, so that the late Daijo blades are the founder under a second name. From him the house became a true generational institution: his son the second-generation Omi Daijo Tadahiro carried it forward as its most prolific hand, the third-generation Mutsu no Kami returned its highest finish, and a Tosa no Kami branch took the founder's signature when he set it aside. Around this main line grew a circle of disciples and collateral hands, the waki- or Soba- smiths, several of them, like Yoshiie and Hironori, working as substitute makers whose own signed pieces are therefore scarce.
The school's signature is its steel. Over a forged so tightly it shows no slackness, fine gathers in minute particles until the surface takes on the rice-bran konuka- (also written ) that no other school produces, fine entering throughout and the notably clear and bright. The orthodox temper laid upon it is a or , sometimes tinged with a shallow and , the deep with finely clustered and tightened to a bright clarity, the running straight to a quiet . The founder aimed this toward the school yet departed from it, his tighter and his forging carrying more vigor; the third generation refined it to what the published sources call the strongest and most precise hand of the first three generations. Against that calm register the house also worked a showier one, the mixing , long , and , ordered clove the founder himself had not attempted but the second generation made his own. The branches pushed further from the standard: Tadakuni of the Ogi domain ran more conspicuously than any other hand and reached toward old in his ; Masahiro and Yukihiro favored a flamboyant long- over the calm main line; and the Iyo no Jo Munetsugu line worked apart in the -, building a on with a pointed and a that tends to stand and tone slightly blackish.
A collector seeks -to first for that steel, and reads it the way the appraiser does: a bright lying over a clear, tight konuka- identifies the school before the signature is consulted, and the quiet on the -signed tang confirms the main-line practice. Generation and branch are then told within that frame, the third generation's powerful recalling not his father but his grandfather, the waki- hands set apart by their irregular temper, their file marks and a signature, the Munetsugu line by its . The main line, made in real numbers across so long a span, reaches the market more readily than any master, so a papered example is within reach of a patient collector, while the founder's own work and the finest konuka- of the third generation come to open hands only from time to time. Provenance runs back through the house the school served, blades recorded to Nabeshima Katsushige and Nabeshima Naomoto and passing onward to the Owari Tokugawa, the Satake and the Imperial families; documentary inscriptions sharpen the picture further, a Myoju attesting the founder's discipleship, carving adding flowers to brocade on his late blades, and the gold-inlaid cutting tests of Yamano Kanjuro and Yamano Ka'emon, rare on work, naming the edge as well as the hand.