[Meg78]

Hi--It's funny --your stats are like mine--not all gaijin are a lot bigger....I'm a small girl (damn welsh blood) and I'm 5'1 and about 101-102 pounds....
I find clothes in Japan really really easily and can fit in size s..I LOVE shopping in Japan...It's about a million times better than shopping at home.
You are gonna be A-OK...
Since I first moved to Japan in 2000 I have noticed that girls seem to have "filled out" more---it's a bit more fashionable to be a bit bigger (maybe Ueno Juri type size...not BIG at all just normal)..in 2000 the style was a lot more bone-like.
In any case I think any size is fine as long as you have confidence and style...I feel like the foreign girls who feel negative reactions might find those reactions are based more on a too-casual not fashionable, rumpled clothing style rather than body size. Just a few people here and there I mean. If I hear my Japanese friends or husband makes negative comments about larger foreign girls (verrry rarely) it's always cause the clothes are kind of....hmmm.....not because of weight.