Japanese police departments try to be as visible in the community as possible. Bicycle patrols are common.
Tiny kei cars (660 cc engine) are also used for patrol. This is what Hello Kitty would drive.
For emergency response and highway patrol large Japanese limousine sedans are used such as the Toyota Crown (3.0L V6).
They also use Japanese motorcycles such as the Honda Interceptor (800 cc).
Japanese police often face off with radical political groups. Large forces such as the Tokyo Metropolitan Police also regularly police events and festivals that draw up to 1 million people. They have access to large fleets of specialized riot vehicles.
Large Japanese police departments also have police helicopters.