A kōban is a special type of small building in Japan where police officers work. They are usually found in busy places like train stations or shopping districts.
Think of a kōban as a tiny police station. Inside, there are usually one or two police officers who wear special uniforms and are there to help keep people safe. The police officers at kōbans are trained to help people with things like lost items, lost children or even just directions.
If you ever get lost or need help in a busy area in Japan, look for a kōban - the police officers there are always happy to help!