When they laugh Japanese women often cover their mouths with their hand. This comes from an old Buddhist notion that showing bone is unclean, as well as a horrendous lack of orthodontics in Japan. If you’re a woman you have no obligation to copy this, but you will soon notice how frequently Japanese do this.
Also, it’s polite to initially refuse someone’s offer of help. Japanese may also initially refuse your offer even if they really want it. Traditionally an offer is made 3 times. It may be better to state you’ll carry their bag, call a taxi, etc., instead of pushing them to be polite and refuse.
