The of the Senoo group (妹尾) locate it in , on land that the documents identify as developed by Senoo Taro Kaneyasu, a retainer of the Taira. The forging ground lay in the lower basin of the Takahashi River, east of and so positioned closer to neighboring . The Genki Mekikisho and the Kokon Meizukushi, repeatedly cited across these blades, divide the smiths into the smiths ( kaji) and the Senoo smiths (Senoo kaji); the chief recorded distinction is that names customarily carry the character tsugu (次), which the Senoo smiths rarely use. The blades span the late period to the mid period, and name Noritaka as the progenitor, with members appearing across the corpus as Masatsune, Tsuneto, Koreshige, Yasuie, Hirotsune, Tsunemasa, Moritsune, Tsunazane, Sukezane, Munesada, Tokimasa, Yukizane, Yukimasa, and a Yukikuni. The consistently read the group against rather than , quoting the old phrase that Senoo work "resembles pieces" (-mono ni nitari), while for Masatsune they raise an unresolved question of connection with the contemporaneous Masatsune of the name.
A shared vocabulary recurs through the descriptions. The is forged in or mixed with , the grain often standing slightly (), with adhering , fine , and mottling (, ) that yields a -like crepe texture; the blades carry or a faint . The is a -based line with shallow , mixed with , , and , animated by and , with and and a that frequently takes a subdued () or moist () tendency. The tends to with a turnback, sometimes with . The shows file marks and individual character signatures (jimei) cut in placement. Within this shared frame the mark distinct hands rather than one uniform output: Tsuneto's blade is brighter at the with conspicuous, florid ; the Sukezane of Senoo runs a higher, more brilliant temper with reverse-slanting that the description reads as resembling work; Munesada and Yukizane present a more archaic, subdued bearing; and the several Masatsune blades sit so close to that one carried a Koyu attributing it to Masatsune.
For , the isolate the points that separate Senoo from the it imitates: a prominent and standing in the , the crepe-like , and unambiguous , together with the signing habit that sets the group apart from . Masatsune is named the representative smith, his works not particularly scarce while surviving pieces by the other hands are described as exceedingly rare; Noritaka is treated as founder, and reference works note two generations each for Tsuneto and the Senoo Sukezane, placed across the Hoji, Joei, and Bun'ei eras. Named provenance recorded in the corpus includes a transmitted in the Great Tokugawa house, a Sukezane held in the Ikeda family with its , and a Masatsune held in the Sendai Date family. The present the Senoo smiths as a line standing beside and reaching toward , valued where signed examples survive as source material for study of the individual smiths and of the group as a whole.