It'll take longer than a game of Eurorails, especially on a first attempt. (You'll spend the first half dozen turns - at least - learning where the cities in Japan are! :) It seemed that railbuilding expenses were higher (longer runs, more mountains, more ferries and ocean crossings) but since it's a skinny map it drops off faster toward the end.

Depending on the players, it can also be pretty cutthroat. (For a meagre investment of 2, you can force someone who was building for the land crossing to Fukuoka to detour via the ferry, if they have enough money!) Of course, that kind of play will slow the game down...

For beginners, add 50% to the playing time for Eurorails; for experienced players, it's probably more like 25%.