This shape is called a Watakusi (barbed) yanone and these are getting very difficult to find. This shape is designed to be primarily a flesh cutter. The smith’s name was Shigetaka.
This one has a long nakago at 8.5 in. (21.6cm), the blade is 3-1/16 in. (7.8cm) long and is 1-5/8 in. (4.1cm) wide. The blade’s shoulder is very long, 1-1/8 in. (2.9cm). There is a traditional Inome (boar’s eye) cutout.
The blade is in good condition, no openings, and the shape is very symmetrical. Estimated age: Mid to Late Edo