I make a point of researching local laws that might affect me before traveling to another country. Learning such information can help avoid awkward or dangerous encounters with local police.
That having been said, I also stand by the advice I give every traveler who doesn’t speak the language or know the customs when visiting or living in a foreign country: if you’re ever caught up in a violent situation that might require the police to be involved, RUN. It doesn’t matter if you’re in France and someone decides to randomly punch you in the face, or you’re in South Korea and an old racist starts yelling at you — RUN. This isn’t a matter of right or wrong, but rather a simple risk analysis; if you can’t speak the language and don’t know how the legal system works, you won’t be able to defend yourself when it matters most, i.e. when the accusations are being lobbed. The chance of you just getting processed and forgotten isn’t worth attempting to find justice in a foreign country.
There are a few reasons why I espouse this approach to Japan in particular.
The Japanese police care more about perception than justice.
Many tourists visiting Japan know there are women-only cars operating at peak times in an attempt to reduce groping. What some may not know is many Japanese men are also demanding men-only cars, so they won’t be falsely accused of groping. While the argument that the number of false rape and sexual harassment accusations far exceeds real cases in the US is insulting and laughable… I kind of understand the logic of this in Japan.
Once anyone, Japanese or otherwise, is arrested, there is little to no doubt they’ll confess or be convicted. The conviction rate in Japan hovers at around 99%, and the Japanese police are well known for their intimidating interrogation techniques. Groping cases in particular highlight the flaws of people in Japan knowing these facts, as popularized in the 2006 movie I Just Didn’t Do It. Confessing from the beginning, even when you are innocent, is infinitely more likely to have you get off with a lighter sentence or just a fine. Nearly everyone who goes through the system understands that showing remorse is more important than the truth.
Let’s say you’re a foreign resident of Japan traveling without your zairyu card or a tourist without your passport. Though it’s possible any encounter with the police without your ID may just result in a warning (it’s illegal for non-Japanese citizens to not have identification with them at all times), they are empowered to do a lot more.
Anyone under suspicion of a crime in Japan can be legally detained by the police for up to two days. After that time, if they feel they can still get a confession or just arbitrarily decide to hold you, this imprisonment can be extended for up to 21 more days. A full 23 days behind bars. Without a phone call. Without notifying your embassy. Without visitors. And possibly while breaking into your home to collect evidence.
However, all the points above are inconsequential when compared with the penal system in Japan. Very few things scare me in other countries — terrorism does nothing, while riding on the back of a motorcycle taxi still unnerves me — but knowing I was being sent to Japanese prison would probably make me suicidal.
Japan is a modern country, with modern facilities for its prison population (for the most part — some don’t have heat or air conditioning in harsh weather, which has caused more than a few deaths), so there aren’t nearly as many cases of prison riots, beatings from fellow inmates, and overall chaos like you might see in some developing countries. In fact, the exact opposite is true: prisoners in Japan are so controlled it’s a wonder more don’t go insane.
From the moment you wake up in a Japanese prison, every word you utter and every movement you make is determined by the rules and enforced by the guards. You’re not allowed to speak to other prisoners, with the exception of maybe 10-15 minutes per day, if they allow it. You must sleep in one position, and not shift at all. You can’t slouch when you sit. Imagine being subjected to such rules every day for years while you serve your time.
The bottom line? Don’t break the law in Japan, don’t engage with the police in any country unless you absolutely have to, and be aware that often the only one who cares about justice may be you.