As some other comments mentioned, the way addresses are entered in web forms in Japan is not standardized. So autofill just doesn't work, a lot of the time. It may even seem correct, but then this particular site wants the address to be written differently.. half-width vs full-width characters, for example (and it can be way more complicated than that). It's so complicated to even enter your name that my Japanese wife couldn't get it right on a hotel's web form, whatever she tried. With her Japanese PC. Had to book by phone, in the end (and, as we weren't in Japan at the time, that was a costly phone call)