The other thing Im always asked is "do you like japanese food", like maybe when Im in Japan I eat a packed lunch that I brought with me or just starve myself. Most of the Japanese in my lcollege class dont much like English food they eaither say it makes them fat or its too heavy. As far as the polite thing is concerned, n a busy train from Yokahama therewas this woman with loads of shopping standing trying to hold one of the straps and her shopping I was sat down and asked her in Japanese if she wanted my seat.She just stood there and stared. Eventually I convinced her she could sit down and just as she was going to a guy sat down in the place and just glared at me. Luckily my frined got up from his seat and she sat there instead.
Basically just shows you that there`s no real difference where ever you go London underground Tokyo Metro, the only difference is the trains are nicer on the Metro.