Etiquette in Japan
Eating and drinking
Many Japanese restaurants provide diners with single-use wooden/bamboo chopsticks that must be snapped apart near their tops (which are thicker than the bottoms). As a result, the attachment area may produce small splinters. Rubbing chopsticks together to remove splinters is considered impolite, implying that one thinks the utensils are cheap.
Etiquette in Japan-21