The San'ami line takes its root in Province, where its head smith Kanenori (兼則) worked as one of the so-called Seki Seven Schools. The place Kanenori from the close of the period into the Ōei era of the early , alongside Kanemoto and Kanesada among the representative hands of , and the earliest extant signed of his is appraised as no later than Ōei. A second early smith, Kanekuni (兼国), is recorded as belonging to the San'ami lineage and is judged to predate the group proper; the remote ancestry given for him runs variously to a disciple of Naoe Kanetomo, to Yamato Kanekuni, or to Kanenori, though the note that nothing survives to confirm so distant a descent. From this stock came Hōki no Kami Fujiwara Nobutaka (信高), born at Kami-Ōchi in in 1563 and said to descend from San'ami Kanekuni. After receiving the title Hōki no Kami in Tenshō 9 (1581) he moved to Kiyosu in Owari and, serving Tokugawa Yoshinao, later settled at Nagoya, carrying the line into the early era through a second generation who took the tonsure in 2 (1662).
Across the corpus the is , often closely forged and tending to or flowing grain along the edge, with and a frequent standing of the grain (); a faint whitish cast () marks the older work of Kanenori and Kanekuni. The temper rests on as a base. In the early hands it is a tight, clear (saete) in , sometimes mixed with small , angular elements and pointed , carrying , and scattered . The Nobutaka works open this out: a broad shifting to shallow , with a -flavored edge, deep with unevenly applied and partly coarse, at the , , , , and that climb into the until the upper half reads as . The runs to with , at times , pointed, or , and the early swords keep a slender, high- shape while Nobutaka's carry the wide-bodied, form of the transition. The hand is recognized in this pairing of a flowing with a core that, in the descendants, breaks toward bold .
For , the fix several anchors. In Kanenori's signature the scooped chisel at the fourth stroke of the character (兼) is read as a trait of late through Ōei work, matched in dated Kaneyoshi ; the clear of Kanekuni is likened to a Zenjō Kaneyoshi masterpiece. The jizō-flavored and the -mixed in Nobutaka are named as the surviving stamp of the root beneath his Owari manner, and one of his is recorded as an Inabae-. Provenance runs through the corpus: a Kanekuni bears recording it as the sashiryō of Ōkubo Genban-no-jō Tadanari, lord of Odawara in , worn at the age of ninety-three; Kanenori's descended in the Yamanouchi family. Among the Owari makers beginning with Masatsune, Nobutaka's of extraordinary length is held in particular regard, and the second-generation Nobutaka is judged no less skilled than his father, with the finest extant Nobutaka works counted to his hand.