Book 4–6 months ahead . March and April flights often sell out by January due to peak international interest in cherry blossoms.
Book 2–3 months ahead . January is widely cited as the cheapest month for return flights from the U.S.. Strategic Booking Tips When is The Best Time To Get Tickets? : r/JapanTravelTips when to buy tickets to japan
Booking early is especially critical if you plan to visit during "high demand" windows like cherry blossom season. Book 4–6 months ahead
Book 3–5 months ahead . While stunning, late November is popular for foliage and should be booked earlier. when to buy tickets to japan