This was on the long flute (2.2? Shaku) I made, Playing with my Pinky on the third hole. It was a little painful to play even with the pinky.
There are multiple versions of this Honkyoku. Like allot of honkyoku it is supposed to represent the buddhist concept emptiness. I have read that this is one of the oldest scores known. I think I like them all. Very simple, meditative, even purifying. I think I will play it again sometime.