A Chiyozuru Morihiro Katana (守弘)

Six hundred years old and still in its original length – that fact alone places this katana among the most complete survivals of the early Muromachi period. First generation Morihiro was the son, or possibly adopted son, of Rai Kuniyasu of Yamashiro (Kyôto), and became one of the defining smiths of the Chiyozuru school, which took the Rai tradition north to Echizen province. These smiths were collectively known as Echizen Rai. The Chiyozuru name itself came from founder Kuniyasu, who searched for the right spring water to forge his blades and settled in Takefu in Echizen around 1337. The Morihiro name ran for approximately four generations. This blade carries the two-character signature 守弘 on a well-aged ubu nakago – original and unaltered.

The blade is long and imposing: 78.8 cm with 2.4 cm of curvature, built to be carried on horseback as a tachi in its early life. The jihada is a well-forged itame mixed with nagare and mokume, showing dark swirls of chikei that shift beautifully in light. A shirake-utsuri glows in the ji, a reflection of the hamon that tends to appear on blades from provinces along the Sea of Japan. The hamon is a vibrant ko-gunome-midare with togari, and a pronounced kinsuji tears through the hamon near the kissaki – exactly the kind of dramatic internal activity that earned this sword its NTHK-NPO Yushusaku designation as a Highly Excellent Masterwork. The boshi is hakikake, sweeping across the tip in a manner that demands real skill to execute.

Full-length kakudome bo-hi run the length of both sides of the blade, squared off at the end to form what the PDF describes as an I-beam construction – reducing weight while managing energy loads through the cut. The shirasaya carries a sayagaki by Dr. Kanzan Sato, former co-chairman of the NBTHK, confirming attribution and period. The sword comes with a custom longevity koshirae built around a matsu (pine) theme – the fuchi-kashira attributed to the Sonobe school in Edo, the tsuba to the Nishigaki school from Higo – both certified by the NTHK-NPO.