Japanese? Thrown Vase w/Grainy-Gloss Glaze, Signed

This is ~6 1/4" high, ~4 1/2" wide; weight is ~665 grams. The throat is ~3/8", foot ring is ~2" diameter. Pic 3 is a good indicator of true clay color. Pic 2, lower left corner shows the 'orange-peel?' in the glaze, which is thick an' deeply opaque. The mark is mostly present, enough, hopefully, for some help in identification. Whatever you see I'll be glad to hear...Thanks for lookin'!

 

That mark looks like a stylized archaic script -- I stand to be corrected. Nice.

 

I have seen the symbol on the right hand side on the base of many a 20th C. Japanese piece.

Possibly means gama or 'kiln'

Similar marks here on gotheborg


1509. Mark: Mokusen. The seal mark on the side, suggested to be read either as Sei-yo or Sho yo. On the base a paper label saying 'Shirokiya', currently a Honolulu department store with a long Japanese history. The vase tentatively dated second half of 20th century.