Sujihiki translates as "flesh slicer", which describes its role well. Typically 240 mm to 300 mm long and 34 mm to 40 mm high, the sujihiki blade is perfect for making long cutting movements from heel to toe. A lower blade height decreases friction when cutting and keeps the fibers of the protein you are cutting as intact as possible.
The city of Sanjo in Niigata Prefecture has been famous for its blacksmithing since the 1600s. In the early years, they mainly forged nails by hand. Then, from 1660, different forging techniques were introduced by blacksmiths from Aizu. Thanks to this, the blacksmiths of the city began to diversify their production. The quality of Sanjo's tools and knives enjoyed a strong reputation in Japan at that time, and it still does today.
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.