Japanese culture dictates their citizens to be very polite. They value respect and they show gratitude in the simplest ways. May it be verbal or non verbal. They greet each other with a bow. Sometimes the deeper the bow the more respect the other person gives to the other (If they are senior to you, a teacher, your grandparents) compared to bowing to a colleague or a friend.
There’s no debate about politeness in Japanese culture.
Videos online show just how polite they are in a non verbal manner. When you are in the freeway/high way with them and a vehicle will merge into your lane and you let them, they will say thank you by pushing the hazard button for 2 seconds.
Another video of an Australlian driver how loves driving in Japan because of their politeness:
How about in our country? Do we have non verbal ways to tell drivers a message?
