Akasaka in Province was the seat of a group the records under two names, Senjuin and Akasaka Senjuin, and the documents are consistent on its descent: the line traces to the Yamato Senjuin tradition, whose craftsmen relocated north into . The place that migration around the end of the period, with the group then flourishing into the . According to the Kōsei as cited, the founder was Kuninaga, set around the Jōji years, with the line carrying the Kuninaga name onward to the Meiō era; Kunishige is placed near Kenmu and is represented by surviving work. The smiths the name span this arc: Kuninaga, Kunishige, and Kuniyuki of the ; the joint spear-makers Hironaga and Hiroshige and the ancient smith Tōga of the ; and later hands signing Dōei, Dōin, Yasumichi, or simply Senjuin. The documents also chart a parallel current, the smith Kuniyuki of Tsuruga (signing Esshū or Etsushū) who entered between 6 and 7, alongside Kaneshige and Tametsugu who likewise moved from .
The shared vocabulary of these blades begins in the forging: mixed with that flows toward , with grain that stands out (), , , and a whitish cast () the return to repeatedly. The temper divides along two lines the documents describe as habitual. One is a slender or with , in which the shows fraying () and a enters near the , with , , and , the temper the Senjuin spears carry as "reminiscent of old Yamato blades." The other runs hotter: mixed with , abundant , , , and building toward , the manner that marks the Kuniyuki current. The tends to with and a pointed return. To recognize the hand, the direct attention to the -bearing, whitish carrying Yamato traits of and , set against a base that leans toward emerging - character.
For the documents are explicit that this line "consistently displays a stronger Yamato character" than the otherwise encountered, and that its "stands at a considerable remove from typical workmanship," though the keeps it within that milieu. Signed pieces carrying an individual maker's name are noted as scarce, which raises the documentary weight of the dated and signed examples the single out: the Kuninaga dated gannen, the signed Kunishige and Kuniyuki , and the Esshū Kuniyuki dated Sadaji and whose signatures incorporate Fujiwara. Among named works the cite the ōmi- signed Senjuin with its vermilion-lacquered long-shaft mounting, the joint spear of Hironaga and Hiroshige, and the by Tōga held to copy the Genji treasure Higekiri. Provenance is recorded for the Tōga piece, formerly of Tanzan Shrine in Yamato and donated to the Imperial Household, with two further Tanzan blades assigned to the . The documents place these works across , , and Imperial registers, reading the group as a Yamato offshoot that carried its -grounded manner into while the base turned toward -.