Japan's booking picture is unusual: a handful of things genuinely sell out months ahead, and a great deal of what visitors worry about needs nothing at all.
Book months ahead
The Ghibli Museum. Date-specific tickets released on a schedule, sold through a lottery or a set on-sale date depending on your country, and there are no walk-ups. It sells out fast and this is not negotiable.
Popular ryokan during peak seasons — cherry blossom in late March and early April, autumn colour in November, and New Year. The good ones in Hakone, Kyoto and the onsen towns fill months out.
Accommodation generally during cherry blossom and Golden Week. The whole country travels.
Book weeks ahead
teamLab installations, which use timed entry and fill at weekends.
Sumo, if a tournament coincides with your dates. Six basho a year — Tokyo in January, May and September, Osaka in March, Nagoya in July, Fukuoka in November — with tickets on sale roughly a month before.
Same-day general admission seats are sold in limited numbers each morning at the venue, which means queuing early but works as a fallback.
Reputable restaurants. High-end sushi counters and kaiseki need reservations, sometimes only through a hotel concierge. Many small places decline reservations from strangers entirely, which is a cultural convention rather than rudeness.
Book days ahead or not at all
Temples and shrines. Almost none require booking. Fushimi Inari is open 24 hours and free.
Museums. Timed slots at some, available close in.
Ordinary restaurants. Walk in. Many use ticket machines, which removes the language problem entirely.
Shinkansen. Reserved seats can be bought on the day at machines; non-reserved cars exist on most services. Only during Golden Week and Obon does this become difficult.
Local guides and half-day experiences, which are widely available at short notice.
The rail pass, which is no longer automatic
The JR Pass can now be bought both abroad and inside Japan, so the old advance-purchase advantage has gone.
More importantly, the 2023 price increase changed the arithmetic. At roughly ¥50,000 for seven days against a Tokyo–Kyoto return of about ¥28,000, a two or three-city trip will not recover it.
Do the sum for your actual route. Regional passes — JR Kansai, JR East — cover a smaller area for a fraction and fit most itineraries better.
How to book when the site is in Japanese
Several Japanese booking systems have limited English. Practical workarounds:
Hotel concierges will make restaurant and some activity reservations, and this is a normal service rather than an imposition.
English-language booking platforms exist for most tourist-facing experiences and are worth the small margin when the alternative is a Japanese-only form.
Browser translation handles most of it, with the caveat that names and dates should be checked carefully.
The seasonal warning
Three periods make everything harder: cherry blossom in the last week of March and first of April, Golden Week from 29 April to 5 May, and Obon around mid-August.
In those windows, book accommodation and long-distance transport months ahead or avoid the dates entirely. Outside them, Japan is a country where turning up and booking two days out generally works.