At the turn of the late period, in the imperial capital and around the district that gives the school its name, the curved blade we now recognize as the Japanese sword was first settling into its mature form, and it was here that the school took shape as the earliest stratum of Kyoto forging and the headwater of the whole Yamashiro-. Its founder, Munechika, worked around the Eien era and is counted among the very first smiths whose names survive, known in popular lore as no Kokaji, the Little Smith of ; from his hand descend the Ko-Kyo-mono and, in time, the perfected and lines that follow. The old registers gather the founding generation around him: Yoshiie, transmitted variously as his son or pupil and read by the published sources as a somewhat later hand of the school; Chikamura, transmitted as a son; and a second house, the Gojo group, formed when Kanenaga and Kuninaga, drawn from the Munechika line, settled in the Gojo district of the city. Of these later smiths only a handful (Kanenaga, Kuninaga, Yoshiie, Chikamura) leave reliably signed work, the corpus thin and the scholarship around it candid.
A shared vocabulary binds the school across these hands. The build is the old Kyoto : slender in , the high and deep with standing at the base of the examples, the width narrowing markedly toward a small . The steel is a refined , tightly knit on the best pieces yet inclined to stand here and there into a flowing, open o-, carrying fine laid as a mist, within it, and a faint (read as a soft or -toned ) that reads the work as Kyoto rather than Yamato. Over this classical stance the temper is laid low and archaic: a base into which and enter, and running in, sitting strongly with and sweeping through a bright . Within this single manner the hands diverge. Munechika fires the quietest line, a narrow -toned with , , and a doubling and trebling into and sanjuba around the ; Yoshiie carries that doubled feeling forward, his small taking on and turning above the , a trait the names a viewing point of the school itself; Kanenaga and the Gojo work hold to a laced with , judged more orderly than the founder, the surviving in the where the later Yamashiro runs plainer.
To a blade is to read its antiquity and its refinement together: the slender, deeply archaic form, the -laden Kyoto with standing grain and faint , the low over a bright , and the doubled temper lines that thread back to the Shosoin-associated early works. The standing problem is the homonym, for both Yoshiie and Chikamura share their names with smiths of the and lines; the adjudication rests on the strong, archaic and the manner of signing, the namesakes tending instead to a flamboyant . Munechika holds the summit of the school and of early Japanese forging, graded Sai-jo by Fujishiro, his patrimony including the National Treasure Mikazuki Munechika, counted among the Tenka-Goken; Kanenaga and Yoshiie are graded Jo-jo . The provenance roll belongs to old Kyoto and the great houses: the Mikazuki in the Tokyo National Museum, Munechika's signed carried by Atago Shrine and threaded through Hideyoshi and the Tokugawa; Yoshiie blades in the Kajiki Shimazu, Ikeda, and Owari Tokugawa houses, with the Hachiman-carved in the Tokugawa Art Museum; Kanenaga's work transmitted through the Owari Tokugawa and the Satake. These are heritage pieces held in trust far more often than traded; a of the early school comes to open hands only rarely, and a signed founding-generation blade, of which the published sources accept so few, almost never.