Stamp identification Japanese Arts & Crafts (possibly) Vase

I dont know why I purchase pieces that stump me, most likely because of that fact - the research and identification seem to be as thrilling as the piece itself! I came across this piece last weekend with an interesting impression. At first it struck me as Japanese as the mark reminds me of the symbol for 谷/'Tani'/Valley and the shape/colors/glaze/medium I find consistent with Japanese turn of the century "arts & crafts" style pottery. Although I am doubting my initial assumption of the piece and would love some other opinions (Naomi I know you'll dig deep in your research arsenal!). I find the stamp looks more like a "house" but that leaves me with little to search from. Most of my pieces are Asian which I can identify much easier and I havent dove too far into the European or American kilns yet - especially post-1950's - so your input is definitely appreciated! Thank you!

As a side note, the glaze is not as shiny as it is in the photographs, also it has slight iridescence that's not displayed.

I dont believe its Canadian as far as I can tell and from my current research of American companies, I've found nothing similar. Strangely enough I found another piece marked with the same mark in the store I originally bought this. The piece was a small lidded stoneware jar decorated with bamboo. Which draws me back to my Asian origin. I still have a suspicion it may be Japanese as I find its somewhat similar to Mashiko ware in its design/marking style. However the flat base still eludes me. Anyways thanks for your input!

Unfortunately its just a mark they use at the store for cataloging (much to my dismay as it's pastel and such a chore to remove, I couldnt even get it off the base no matter how much I scrubbed) but I thought it looked like a kanji character as well!