The published sources open the record with a document older than any blade: the early eleventh-century Sarugakki, listing the notable products of the provinces, already names "the swords of Bicchu". The smiths of the lower Takahashi River basin inherited that reputation, the work up to about the middle of the period being called and the later work through the period . Sadatsugu is "a representative smith of the forges", and the name was carried on within the school down to the period.
The same sources are frank about what that means for the name. Among works signed Sadatsugu there are signatures in a small manner, signatures of ordinary proportion, and others that look somewhat later, so that the smith "is thought not to have been one man". The signed of the 22nd session, with its small-style two-character , is read as a work "of a somewhat later date even within ".
That gives the type. It is with , deep in , with a . The signature sits on the near the , toward the , on an tang filed in steep . The forging is mixed with , inclining to toward the edge, with and patches of . Over it runs a narrow , its drawn somewhat tight with , and the goes straight to a .
The shortened blade of the 70th session shows the same manner over a finer . Its is well packed, with thick and plentiful , and a patchy, -toned rises in the . The carries a little and slight , -dominant with , with near the on the . The published sources find in "the orderly with suitably blended ", together with the fine and the calm, gentle , "a piece that conveys the dignity of the school". Its several peg-holes show it was shortened more than once, and at some stage the folded-back signature was repaired and remade into the present affixed inscription, reading "Sadatsugu, resident of Bicchu Province".
Two Important Cultural Properties carry the record further, on plates that give only form, forging and temper. The signed held by the State at the Tokyo National Museum is forged in mixed with and tempered in a with and mixed in. The known as Ō- was shortened and gold-inlaid with his name and a attestation; it is forged in and tempered in a .
Four designated works stand on record: two Important Cultural Properties and two . The Important Cultural Properties are national patrimony and do not change hands, one of them in the State collection. The two blades, both of the quiet manner, are the part of the record a collector could ever meet, so a signed Sadatsugu reaches the market only rarely and is an occasion when it does.