Making a tachi blade with the water from Mt. Haguro in Yamagata prefecture
When Kokaji visited Mt. Haguro he saw old Gassan tachi blades from 14th century in the museum there. Then, he was inspired to make an old Gassan style tachi blade with the water what took from the waterfall in the mountain.
Forging the blade
Gassan blades are famous for their unique Ayasugi pattern of steel layer. But, the smith thinks that the essence of Gassan blades is not the layer pattern, but the simple way of steel construction. That is sandwich style "three layer steel construction". Then, he planed to make a tachi blade as simple like old Gassan blades.
Outer steel : for the surface of the blade
Pick up random quality tamahagane pieces, and start fold'n welding work. Forged out after 11time foldings.
Core steel : for the edge
Pick up hard pieces of tamahagane. And forged out after 11 time foldings.
Construction
The core steel and outer steel are constructed in sandwich style, and drawn out roughly.