Chopsticks were first introduced to Japan about 2,000 years ago.  

The formal etiquette for using chopsticks was in place by the 1600's.  

Using Chopsticks

Pick up chopsticks, ohashi, with the right hand.  Rest chopsticks in the left hand while placing them in the proper position in the right hand.

Place the chopsticks on the rest, hashi-oki  in between bites. They may also be placed on the side of a dish or saucer if a hashi-oki is not provided.  It is not proper for the chopsticks to touch the tray or table after you have started eating.

When finished, lay them across the plate, or rice bowl. Some people put them back in the paper they came in and bend a corner.

In a formal situation it is proper to lay the chopsticks down when being served.

In more formal, expensive restaurants you may receive lacquer chopsticks that are placed on the hashi-oki.  These are slick and more difficult to use.

When taking food from a communal plate, do not use the end of the chopsticks that you put in your mouth.  Reverse the chopsticks and use the unused end to take food.  Always use serving chopsticks if they are available.

Most restaurants serve wooden chopsticks that come in paper wrappers and need to be separated before using. Cheap wooden chopsticks often splinter when pulled apart and people are often seen scraping off the splinters.  Be cautious here--scraping the chopsticks might offend your host, indicating that you are being entertained in a cheap restaurant.