The Bunka is a general purpose knife that has a straighter edge profile than a Santoku. This makes the rocking motion more difficult to perform. However, the Bunka is perfect for use with the push-cut or pull-cut method. Its fine tip provides precision and agility as it passes more easily through the food when cutting.
Simply explained, Aogami #2 developed by Hitachi Metals is a steel made from Shirogami #2 in which some chromium and tungsten are added for better durability and corrosion resistance. In addition to that, the higher carbon content of the steel allows for better cutting retention. Objectively, the Aogami #2 is an improvement over the Shirogami #2. For patina lovers, however, Shirogami steel will be more reactive to oxidation and could be an advantage.