Dude I just did some research and it turns out that the 'kumoi' scale is actually just the minor 6th pentatonic (a pentatonic made from the melodic minor scale. John Coltrane uses it a lot) and actually goes like this:

------------------------------
------------------------------
------------------------------
----------------5-------------
---------7--9-----------------
-5--7-8-----------------------

Amin 'Kumoi' scale (or Am6 pentatonic)

The scale you have been using is just an aeolian (or natural minor scale) without the 7th degree.