This is a large yanone and, in fact, it seems too large to have been practical for use. For this reason it is most likely a smaller presentation Yanone. It is signed on the blade with a two-character signature. The mei is difficult to read, perhaps Naokuni. This placement of the mei is often seen when a blade has a large flat area above the shoulder such as this one.
As can be seen, there are significant hataraki (activities) visible on the blade. The hamon is suguha with thins wispy areas of nie exuding from the hamon. The hada is masame to a running masame. There are some rust areas and there is a hole on one face that is 1mm or so deep.
The nakago shows good age (early to mid Edo). This yanone is 15-1/4” (38.7cm) long with the blade being 4-3/8” (11.1cm) long by 1-3/4” (4.5cm) wide.