Serving chopsticks, called *toribashi* in Japanese, are a separate pair used to move food from a shared plate or hot pot onto your own plate. Using the same chopsticks you eat with to take food directly from a shared dish is called *jikabashi*.
Using your own chopsticks at a family meal is not unusual in Japan. The same behavior at a work dinner or a meal with people you do not know well can make others very uncomfortable. There is no single rule that applies to every shared dish. How people feel about *jikabashi* changes greatly depending on their relationship with the other diners.
When serving chopsticks have been provided, using them is the normal choice. There is little reason to put your eating chopsticks into food that everyone is sharing. Someone who ignores the serving chopsticks sitting in front of them may be seen as inconsiderate or lacking basic table manners.
Family meals are different. Some families place a large dish in the middle of the table and let everyone take food with their own chopsticks. People are not usually thinking about hygiene every time they take something from the dish. It simply works as the usual way of eating within that family. The same may happen among very close friends.
At a work dinner, asking a server for serving chopsticks is the safest option if none have been provided. Another option is to use your own chopsticks before you have eaten with them and serve everyone first. Some people reverse their chopsticks and use the handle ends. This is not necessarily the ideal solution, but it does show that they are trying not to use the ends that have been in their mouth.
A visitor who does not know this custom may use their own chopsticks without meaning any harm. Other diners may understand that the person simply did not know, but the discomfort may remain. No one may say anything, yet people may quietly stop reaching for that dish afterward.
Something that feels completely normal within a family can suddenly feel unpleasant when the people at the table are not as close. Serving chopsticks are not only about hygiene. They also reflect how comfortable people are sharing food with one another.