I’ll be traveling around Japan in May and a friend advised me to buy a green JR pass instead of a normal one because he said reserved seats tend to be sold out in the high season.
When I looked it up, answers seem te differate. JR says that May, August and September are the busiest months to travel by train but on some tourist sites May is classified as a medium busy month.
How likely is it you think that seats are sold out during May? And is standing avoidable is you travel really early or late?
There’s usually no problem in getting seats if you book a few hours in advance, even during foreign tourist high season - the green car pass isn’t really necessary unless the extra price for convenience fits your budget.
By seats being “sold out”, your friend probably means reservations for trains when you turn up and book a slot just before you travel. Play it safe and book your reservations a day or two before you plan on traveling.
The specific dates of the start and end of Golden week are perhaps the only time when you might need to book a little further in advance - this is when lots of Japanese people go on holiday round the country, and is probably peak train usage during the year.
