ID help for Japanese studio vase

Can anyone help identify the maker of this Japanese stoneware vase in moss-green glaze with incised decoration? (it was sold to me as '20thC Japanese,' and the type of glaze is common in Japan, but I suppose the impressed Chinese characters on the base could also be read as either a Chinese or Korean name.)

The whimical style of the impressed mark suggests to me that the vase was factory made for the Western market. Don't know where because the style doesn't have any oriental characteristics that I recognise.