Identify this Japanese knife?
You may know this already. It is a deba-bocho (a single bevel fish knife). It is Japanese fish butcher/filet knife. I know the Japanese characters for the knife, but I am not familiar with this brand. It basically states that it is "Deer Brand". Sorry. I don't know anymore beyond this brand.
In term of sharpening, there are a few nice videos for single bevel knives. If you just want to do it like most home cooks, here is a good one. It also includes how to use it to filet a fish.
If you want to do a very good job, then Jon has a very nice video:
Deba's are good knives. As Chem suggested, try it with boned chicken pieces. I think you will be surprised how well it works. Being single bevel, it will be hard to get flat straight cuts in hard vegtables but, those are fun to cut too.
It is a carbon steel knife so, you need to keep it lightly oiled to prevent rust staining. With use, it will develop a patina which will help protect it from rust.