10) Misuse Your Shoes
Thresholds at businesses and all homes and apartments in Japan have a convenient place for you to store your shoes and don borrowed slippers for your journey. However, did you know you should never wear slippers on tatami mats? It's also a huge cultural faux-pas to come out of the bathroom still wearing toilet slippers, as they've been rubbing on dirty linoleum (although this even slips Japanese minds from time to time).