I wouldn't say you needed oversized t-shirts to go with Yohji though. It depends on what you want to go for of course, but I have quite a few round neck t-shirts that look pretty alright with Yohji clothing that I have picked up from a number of different brands. Some are figure hugging and others are cut pretty loose, but none of them would be considered oversized I don't think. Merz B Schwanen makes pretty substantial tshirts and I have a few of those. Probably more expensive than Muji stuff, but I am sure they should be available on sale.
Will take photos of the suit once it arrives.
And as a mini-review of my own experience with Fromjapan, bottom line is I am impressed. Very seamless transaction from start to finish. I chose their safer packaging option and got the sunglasses in this relatively big box filled with bubble wrap, lol. Feel bad as it seemed like such a waste to package a pair of sunglasses in something so big, but the packaging was done very well. So if anyone else feels like using them I can recommend them based on my initial experience. Made the purchase of the zipper suit with them as well so will see whether the second transaction works out.
A possible problem that could come up with them I think is that since some sellers on Y! cancel sales to Y! accounts that are proxies, it is possible that this may happen with their own accounts considering they seem to be named pretty closely to the site name, but I dunno. Just something to think about as well.