I'm so traumatized by my suddenly L frame that I can barely write in complete sentences.
By Japanese standards, I'm huge. Yes, I'm technically half Japanese, but my Japanese half is from Okinawa, where the women actually have hips. The women on mainland Japan are stick figures. And they like knowing they're small, so the stores here are stocked with XS, S, M and maybe one or two L.
At one of the games on our baseball tour, I bought an L-sized T-shirt at the Hanshin Tigers gift shop. It barely fits; it's almost too tight. So when I decided to go shopping for cute Japanese outfits, I made sure the tops were L, which was heartbreaking and demoralizing, yet necessary. I managed to squeeze into an M-sized skirt, but then I made the mistake of deciding I could buy a pair of cute pants at the Japanese clothing store Comme Ça Ism. That's when I had the unable-to-button incident. I was blue the rest of the day.
To cheer me up, Marc googled "Westerners finding clothes that fit in Tokyo" and found other women in my situation. Here's one from a woman my size. Here's a forum on japan-guide.com that tries to answer clothing questions from women who are several sizes larger than I am. (Of course, I felt much better when I read that one.)