Japanese Spatial Terms (for reference)

Mu:
(the void) 

no, not, nothing, or without
nothing, not, nothingness, un-, is not, has not, not any
Nonexistence; nonbeing; not having; a lack of, without

Ma:
(in between space)
gap, space, pause as experienced as an interval in spatial design
experiential space as experienced through intervals in design

Oku:
(inwardness)
roughly translated as inward space lying somewhere in the deep end
like an onion-skin, the idea there is always something more to be revealed, to encourage moving deeper