Do Not Mess With Chopsticks
Chopsticks get used by the Japanese on many occasions. For eating purposes only, however. People do try to avoid using them for anything other than eating as they might carry human saliva. You should also never wave your chopsticks or use them to point at things, especially; if you wave them over food.
In Japan, chopsticks also get viewed as an important piece of culture – meaning they should get treated with tons of respect. The very act of playing with it or using chopsticks, what one might consider unnecessarily, IS considered disrespectful. You can always look on YouTube to figure out how to best use chopsticks.