What is the name of this style of knife? Several years ago I found this knife at a thrift store: 



I like this knife a lot because it is very effective at transmitting force to the food I am cutting. But I am anxious because I do not know how to find a replacement if this one breaks or is lost. Does this style of knife (where the handle is directly above the blade so you can transmit force vertically) have a name I can type into a search engine?
I believe it is a frozen food saw. The serration is very small like you would need to saw through frozen fish for example. Given that it was made in Japan, I believe it is a YAX brand knife/saw. While I couldn't find that exact style from them, they did make some that were very similar.

Google Image Search "yax frozen food saw" and you'll see several.