Safety in Japan
Japan is one of the world's safest cities
I have heard from some of my foreigner friends that in some countries, people would rather avoid getting involve with the police than seek justice for a small problem. In Japan, you don't have to worry about the police taking advantage of you. Although they can be a hassle at times do the the amount of time it takes to get anything done with them, they will never take advantage of you. Japanese police officers are usually friendly and there to help you.
People probably use the small police stations (Koban) the most for asking directions. Policemen are the best people to ask for directions whenever you are lost and at Shinjuku station I have seen people lining up to ask a policemen for directions. The Koban is also a place where you can go when you have lost something. If someone hands your lost item to the police somewhere in Japan, a notice will arrive to where you handed your file and you will get your item back. This is really wise to do since things are often handed back to the police in Japan.
The Koban is also a place where you can run into if you are in an emergency. However be careful, policemen are sometimes on patrol and the police station is unmanned. In that case, pick up the phone on the desk and you will be connected to a policeman. Sometimes, they are on break in the back room and will be able to help you immediately.
The police in Japan are there to help so please don't hesitate to approach them. With such little crime in this country, they need you to keep them busy!