rules on eating on public transport It’s fine to eat bento boxes or other foods bought from the onboard service on trains like shinkansen, but eating and drinking on other public transport is often thought to be impolite. Drinking from a plastic bottle or eating candy or gum are fine, but anything larger, like snacks or onigiri or sandwiches, might be thought of as unpleasant by the other passengers. Fast food and other strong smelling food should definitely be avoided. You should also avoid eating on busy trains as there is a chance that you might accidentally spill your food or drink on someone if the train shakes. This is especially true on the city trains, which can become extermly busy