This is a shinsakuto (modern sword) by the Osaka smith, Sadaharu. He was the second generation of smiths of this name. His father worked around the Meiji era. This sword is signed Settsu Ju Kawai Minamoto Sadaharu Kore o Tsukuru. It is dated as being made in March of the 50th year of Showa or 1975. Sadaharu studied with Gassan Sadakatsu and then with Gassan Sadakazu, the Living National Treasure smith (they were probably contemporary). Sadaharu’s speciality was swords in the Soshu tradition and more particularly those of Sadamune. This sword is reflective of that.
This is a very strong sword with a cutting edge of 28.5 inches or 72.5 cm. It has a moto-haba of 1.24 inches or 3.2 cm and a saki-haba of 2.3 cm. The hada is a very tight ko-itame almost a mu-ji hada. The hamon is a notare-midare with lots of nie in and around the habuchi. It is a very pretty sword. If you are a collector of the Gassan school of swordmaking, this would be an important addition to your collection as blades by Sadaharu are not so common. It comes in a shirasaya with a solid silver habaki.