In general when looking for the cheapest flight to Tokyo, try to book your flight during the month of February for the best deal.
On average, from most locations, when planning your trip to Tokyo, try to book your flight in the region of 53 days in advance for the cheapest prices.
From most locations, the cheapest day to fly to Tokyo is Monday. Most users found that departing on a Friday was most expensive.
Typically, cheap prices to Tokyo are most often found for evening flights. Cheap prices are less likely for midday flights.