Explanation:
You could be nice to the other person when they win and you don't.
If you win then you shouldn't brag.
Play fair
I don't know about Japan, but Germany had a real love hate relationship with Coca Cola. There was a great deal of maneuvering to satisfy both parties. There is an interesting footnote. Germany thought Coca Cola was "too American" for it to be exposed to the German people. (That is likely the answer you are looking for). So Coke changed the product's name to Fanta. I don't think the Fanta we drink today is related.
The logo that Coke developed in Germany was a swastika with coke or coca cola plastered all over it.
