In Japan, you are conditioned to care- even if too much.
One of the first things I had to learn was to separate my trash. After 24 years of dumping all my rubbish into a single bin, I had to begin categorizing them into combustibles, non-combustibles, glass, plastic and cans. It took me two weeks to figure out what went where, and I remember P being constantly annoyed that I could not apply common sense to my garbage disposal.
Something else I learnt was that eating on the go is considered very rude here. Despite the constant rush of the city, try biting into a sandwich or drinking coffee while walking down the streets and be prepared to be stared at.
A third peculiarity of the Japanese is that while they can tolerate noisy banter, lewd men and drunken salarymen on the train, talking on your mobile phone is prohibited. If you are near the priority seats, you are expected to turn it off. I still pick up calls unknowingly sometimes, but I speak in hushed whispers and in English, so I get excused for being the ignorant gaijin.
Another way to tell if you are foreign is if you leave the theatre right after the last scene of the movie. Here the people sit through the closing credits as a form of respect to the moviemakers, and they wait till the lights come back on and the staff announces that it is over before they leave their seats.
Most days I am happy to adhere to the social norms here, but there are days I ask myself why on earth everything has to be done for appearance sake here.
A piece of advice I hear often is that you either submit to the system or pack your bags and leave. There's no room for gray area.