The day after we arrived in Japan for the first time Mya and I did a Sushi cooking class in Asakusa. It was an excellent idea (in hindsight) as our beautiful teacher, Yoshimi-Sensei, armed us with some essential local knowledge, including hashi etiquette. Hashi, or chopsticks, are, of course found in many other countries. However, the Japanese use them as part of their funerary ritual, so some faux pas are pretty big no-nos and, as in all aspects of Japanese life, there is an expected level of manners.
The two biggest taboos when using hashi are standing your hashi straight up in rice. This is how rice is offered to the dead. And, passing food from one pair of hashi to another. The Japanese do this only during a funeral when remains are passed with hashi. These two unspoken rules are the most important…. I made sure my kids were very clear on these ones.
In addition to this you should never stir your food or dig through it with your hashi, never use them to drum on the table or crockery, don’t point with them, don’t click them together, don’t wave them over the food in indecision, never spear your food with them, do not chew, lick or bite them and don’t hold one in each hand to use them like cutlery. Also, never hold your rice bowl and hashi in the same hand, and always use your chopstick rest. It is rude to lay your chopsticks over the bowl. However, many of my Japanese friends say this is becoming less of a thing, as many izakaya and other casual dining establishments do not offer a chopstick rest. You will, however, always find them in soba, tempura and kaiseki restaurants. All traditional places will have them. I sometimes use the wrapper of the wet towel, if I am stuck.
Oh, and the wet towel is to wipe your hands BEFORE you eat.
The cooking class we did in Tokyo was excellent, I have returned to do a second class since. Yoshimi is very knowledgeable and lived in Canada for a time. Her English is excellent. I highly recommend TOKYO KITCHEN Japanese Cooking Class. You can read about my experience here and here.