Some time earlier this year, I decided it was in my best interest to stay away from the news-based or impersonal English language sites that cater to people living in Japan. The reason I made this decision was that most of those sites seem to be ran by and commented on by people who are so deeply steeped in being a foreigner in a foreign land that they have a worldview entirely shaped by it. Many of them have extremely rigid views of what a foreign person should do while living in Japan and have disdain for anyone who doesn't fit their definition.
A recent discussion with a student about the Yamanote line Halloween party compelled me to revisit one of those sites (it ends with "Probe" and starts with the name of the country it's about). For those who don't know, the Yamanote line is a train line which travels around central Tokyo in a huge loop. It's often packed with commuters, shoppers, etc. and trains arrive at stations at very frequent intervals (about 3 minutes apart). She told me that she'd seen on the news that police were gathered to deal with the party this year, but she was unclear as to why that was the case. In the interest of clarifying the situation for her, I ventured into hostile territory.
I'm not going to debate whether or not the party is a good or bad idea, because I've never attended one of them and only have second hand information about how disruptive or festive it is. And frankly, I don't care. Just because I'm a foreigner, it doesn't mean that the actions of other foreigners have to be of paramount interest to me.
When these sorts of controversial situations come up, there are always people who assert that the people who behave in ways they view as inappropriate for Japanese culture are making us all look bad. Their viewpoint is that we should all be paragons so the natives won't generalize the bad behavior of one person or party to all of us. They say this knowing that this standard doesn't apply to Japanese people, who are far from all acting perfectly in public (very, very far).
The notion that we must behave well so as not to make others look bad by association is based on a very real mindset among some Japanese. That is, they see one foreign person causing trouble and nod their heads and say that's what you have to expect from foreigners. Many of them already believe we're all ill-mannered and bad behavior from one person confirms their prejudice. The crux of my point is that people who already hold a prejudice and are just looking for confirmation are never going to view foreigners differently, no matter how perfectly mannered they are.
Being the most obedient foreigner you can be isn't going to change any one's mind about how foreigner's in general behave. They'll see you as an exception to the rule, not as an example of the rule.