Blowing Edge of Myoan Fuke Shakuhachi（明暗普化尺八）
The sound of the traditional Japanese bamboo flute can be determined by various conditions, such as finger-hole positions, sizes, wall thickness, not to mention the inner structure the bore. The blowing edge (Utaguchi), also has an extremely effective role in the overall sound.
Gyokusui Myoan Fuke Shakuhachi is made under certain rules (see Fuke-Shakuhachi) and it has a thicker blowing edge called, Ubaguchi. （婆口）
The Ubaguchi helps the Shakuhachi harmonize individual notes together.
It requires forceful blowing pressure because of its angle to the bore axis, which makes it perfect for Kusabibuki, the authentic way of playing of Fuke Shakuhachi.