My dad had a spade very similar to your Japanese gold, but the handle was made of wood, the blade was the same shape but a bit shorter. This was about 40 years ago, I wonder where it is now, we will never know.For anyone interested in this best thing since sliced bread , this is the American version. Not as sharp a point as the Irish and with treads. The Irish makes better dome shaped holes. This one you can really cut down hard.
For digging or shovelling they don’t half save your back. View attachment 44248
Right is my American spade, middle the Japanese gold spade ( a little digging machine) the blade shape penetrates really well especially when there’s roots and a great planting tool.
And left the ladies fork for repairing footmarks on the border( not for heavy work!).essential for good soil