Wakizashi by the famous top student of Horikawa Kunihiro. Jojo-saku smith rated. Per the NBTHK:

Dewa-daijo Kunimichi’s dated blades are seen from the Keicho (1596-1614) to Kanbun (1661-72) periods. As far as we know today, his active period extended over 50 years. Because of this, his blades are seen with Keicho Shinto to Kanbun Shinto shapes. From his signature styles, this katana is supposed to have been made during the Meireki period (1655-57) or somewhat earlier or later, but the shape is a Kambun Shinto shape. The jihada is itame mixed with mokume, the hada is visible and called a zanguri (rough) jihada. The hamon is ko-notare mixed with gunome, togariba, and yahazu choji.

This is an extremely interesting sword, with a wide gunome-chogi on one side and the other is more Shizu-based with long streams of nie. In shirasaya with tsunoguchi and a gold foil habaki. Two sets of NBTHK papers. Formerly from the collection of Arnold Frenzel.