@wimleers@wolfr@iworx Watch out though! Prices of rail passes will go way up from next week, so be sure to do the math.
In my experience, you can just go without up front reservation. There’s a high frequency of trains, including the high speed trains. Going to the station 30-45 min in advance to book a seat for Shinkansen and you should be good. For other trains just jump on with PASMO.