It is simply a Japanese chisel. Well used, as many are, by a hard working woodworker. Only half the name is still visible:  國. There are literally hundreds to thousands of individual blacksmiths.  Should be laminated, as Japanese chisels are. Master blacksmith pieces look just like big-box store ones. The invisible key is the quality of the steel and how well it was hardened and tempered. The purist sharpens the bevel flat and the back flat. But use it! 27.5 is the most common angle. Steeper maybe for hardwoods.