Listing a very long Kamakura period blade attributed to the Yamashiro school Ayanokoji. This group is generally felt to have started in the middle Kamakura period with the smith Sadatoshi. I believe this is an earlier example, also in the middle Kamakura time period. Markus Sesko has an excellent article on the school at the link below.

https://markussesko.com/2015/09/06/kantei-4-yamashiro-5-ayanokoji-綾小路-school

This is a typical example. The hamon is a very complex assemblage of choji-midare and gunome-midare, with tobiyaki and sunagashi throughout. The jihada is generally ko-itame, but there are coarser areas and a few openings. The blade is very old and shows its age in places, but Yamashiro blades from this time period are not readily available and remains a nice example to study. The previous owner had the sword papered with the NBTHK (Tokubetsu Hozon) but lost the kanteisho. It is consequentially being offered for a price well below his original cost. I have attached photos of the previous kanteisho here

YAMASHIRO AYAnoKOJI School

AYANOKOJI are similar to SANJO. SANJO and GOJO smith lines were generally the feeder-source. KO-MOKUME HADA. KO-CHOJI KO-MIDARE. Double-petal CHOJI. The school is renowned for refined beauty.

SADATOSHI JO-EI: AYANOKOJI Founder at YOJO AYANOKOJI. YATARO.
Buddhist name: RYOAMI. A GOJO line smith, his time was the transition between early KAMAKURA and mid. Work period estimated as starting around SHO-KYU 1219 and continuing through the `40s, although his dates are often
listed as later. One source claims him a son of RAI KUNIYOSHI, which goes with an attendant theory that GOJO  to AYANOKOJI SADATOSHI and contemporary RAI KUNIYUKI (AWATAGUCHI KUNIYOSHI son) traded secrets or were peers as both show CHOJI patterns with distinct similarities. SADATOSHI has inter-linked TOBI-like JI-BA and a plainly starker definition, where KUNIYUKI (as all RAI School) endeavored width of YAKIBA through the BOSHI. The BOSHI of KUNIYUKI and his father, KUNIYOSHI is generally smooth. The consistency of SADATOSHI’s CHOJI line may seem broken from happenstantial effects at the quench. An otherwise absent high-reaching CHOJI leaves dotting SHIMA-BA to remind its departure. This presumed confidence has been much appreciated over the years. The technique masks a YAKIBA plan with a similar width to that of RAI but the SADATOSHI BOSHI would be not smooth. His SUGATA was made to reflect a grace found of earlier pieces, while the usual KUNIYUKI is solidly mid-KAMAKURA. SADATOSHI was perhaps, a little earlier than RAI’s KUNIYUKI. SUGATA will be deep KOSHIZORI, KO-KISSAKI TACHI. Seemingly even, the measure shows FUNBARI. KO-KISSAKI can be an elongated or reaching IKUBI. A JI-NIE veil dresses standing KO-MOKUME that runs. KO-NIE in clear NIOI-FUKASHI presents “Flower-petal” KO-CHOJI or KO-GUNOME that is KO-MIDARE. HAMON shows small TOBI-YAKI that seem connected together. MEI: SADA is large, TOSHI – small. The SADA appears as though someone erased its left side.

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