Black-forged naginata-bocho.
Shirogami white#1 steel. Japanese cherry handle.
Hand-forged on Tanegashima Island.

'Naginata' usually refers to the long pole weapon - do a search on wikipedia and you'll see a similarity in the shape of the blades.

The naginata knife is first and foremost a tool for fishmongers and fish processors, for breaking down and filleting large fish. In this case, very large fish. The rounded blade end is particularly convenient for slicing from head to tail down the spine. 

We'll be straight. The Toku-Dai ("special big") 270mm naginata is a monster, the biggest knife we sell. We refer to it as our Middle-Earth knife. If you need to break down large fish and you can bring those fish to this knife, then it may make sense for you. This naginata is long, thick and heavy, with a very large handle. You need strength and technique to use this knife. If we had to classify it, it would likely be under Professional Use Only.

If you purchase this knife because you think it's novel, well, we warned you.