Whether you should sleep on a flight to Japan depends on your arrival time and the direction you are traveling. If you are flying from the US or Europe and arriving in Japan in the morning or afternoon, you should try to sleep during the latter half of the flight to align your body clock with the new time zone. Most frequent flyers recommend staying awake for the first meal, then taking a nap so you wake up just as "breakfast" is served before landing. However, if you arrive in the evening, you should stay awake as much as possible on the plane so you are exhausted enough to go to bed at a normal hour (9:00 PM or 10:00 PM) in Tokyo. The "golden rule" of Japan travel is to avoid napping upon arrival; staying awake until the local evening is the fastest way to beat the 12-to-14-hour jet lag.