Japan has no dirt-cheap route from Europe or Australasia — the distances are long and the Tokyo airport pair (Narita and Haneda) is dominated by full-service carriers. That said, price variance across the calendar is significant enough that booking timing matters more than airline loyalty. The optimal booking window for long-haul from Europe is eleven to fourteen weeks out; from Australia and Southeast Asia, six to eight weeks is sufficient because the intra-Asia market moves faster and oversupply keeps fares lower than the transatlantic model.

Haneda (HND) is the better airport for most itineraries: it sits thirty minutes from central Tokyo on the Keikyu or monorail, and its domestic terminal connects directly to Shinkansen onward travel. Narita (NRT) is forty-five minutes to an hour further out and best accepted when the fare differential is meaningful — anything over £80 or $120 USD justifies it. Osaka’s Kansai International (KIX) is underused as an entry point: prices from London to KIX are often £50-£100 cheaper than Tokyo, and Kyoto and Nara are reachable within thirty minutes of landing. The trip structure of flying in to KIX and out of HND (open-jaw) is the most efficient frame for a two-week itinerary.

From London, the typical economy return outside peak season sits between £700 and £1,000. August and the two weeks around Christmas push fares to £1,100-£1,400 and availability tightens early. The golden window is late February through mid-March (before cherry blossom peak) and mid-October through mid-November (autumn colour without the summer crowds): both deliver reliable economy returns around the £750-£850 mark. Japan Airlines and ANA fly direct from Heathrow; British Airways codeshares on the JL route. Indirect routings via Helsinki (Finnair), Helsinki via Cathay via Hong Kong, or via Seoul (Korean Air, Asiana) regularly undercut direct fares by £100-£200 and add only three to five hours total journey time — worth taking seriously.

From Sydney, return economy to Tokyo sits between AUD $900 and $1,400 in non-peak months. Qantas flies direct (around nine hours); Japan Airlines, ANA, and Jetstar operate the route. Jetstar’s direct Sydney-Osaka service is worth knowing: it frequently prices AUD $500-$700 return in the off-peak and serves the KIX open-jaw entry point directly.

The low-cost versus full-service trade-off resolves clearly on long-haul: there are no serious LCC options on Europe-Japan beyond Jetstar’s narrow network. For the intra-Asia market — if you’re arriving from Bangkok, Singapore, or Hong Kong — Peach, Jetstar Japan, and Vanilla Air all operate domestic and near-international routes from Tokyo and Osaka at prices that make the JR Pass irrelevant for short hops. A Peach fare from Tokyo to Sapporo can be found for ¥3,000-¥6,000 one-way booked a few weeks out.

Use a flight comparator rather than going direct to a single airline until you’re ready to commit. Aviasales aggregates the full matrix — routing permutations, open-jaw options, flexible-date grids — in a single interface. It consistently surfaces Korean Air and Finnair indirect fares that the individual airline sites either bury or price inconsistently. Kiwi.com is the stronger alternative if you want to build a multi-city itinerary with separate legs under one search (Tokyo in, Osaka out, with domestic segments between them). Kiwi adds value specifically when the open-jaw or multi-city routing would require manual combination elsewhere; for a straight return, Aviasales is faster. Once you have your routing, booking direct with the carrier is usually identical in price and removes a third-party layer if anything needs to change.

Japan’s quirk in the air is its domestic network. The Shinkansen earns its reputation, but it is not always the right tool: the Shinkansen to Hokkaido takes over four hours from Tokyo, and flights from Haneda to New Chitose (Sapporo) take ninety minutes and cost ¥8,000-¥15,000 on a domestic carrier. If Hokkaido or Okinawa is on the itinerary, build in at least one domestic flight and search it separately from the international leg on Aviasales rather than pricing the full itinerary as a package.