This is a fine katana by Jirotaro Naokatsu. Naokatsu was the son of one of the most famous Shinshinto smiths, Naotane. Naokatsu worked around 1830-1850. He died in 1858 at the age of 54, one year after the death of Naotane, his adopted father. He is rated at Jo-Jo saku and is more highly evaluated than Naotane by some. His frist name was Kazusa Jiro and later Jirotaro. He lived in Edo in the Shitaya area. This blade is signed Jirotaro Naokatsu and is dated as being made in the 11th year of Tenpo or 1840. This would mean that he made this blade when he was 36 years old and at the height of his strength and ability.
It is a long blade measuring 31 and11/16 inches or 80.45 cm. It is wide and strong with a motohaba of 1 3/8 inches or 3.5 cm. The hada is a very tight ko-itame hada as one would expect on a Shinshinto blade. With this blade he succeeded in capturing the fine Bizen blades of the Nanbokucho era. There is absolutely outstanding utsuri covering the ji. There are very few smiiths even today who could create this kind of midare utsrui. The hamon is a ko-choji with ashi done in a suguha style.
It comes with Hozon papers that attest to its quality and authenticity. It is in excellent polish with no flaws.