I am arriving at Narita Airport on Mon 9 April at 7pm and so until then I am not able to exchange the documents for the actual rail pass. I would like to travel on the N'EX to Tokyo then catch Sunrise Seto to Okayama the same night. It appears the only way I would get a place on Sunrise Seto is to reserve well before then.
Are there any sitting up seats on Sunrise Seto? Is it possible to make a reservation from outside Japan (if it is made in Japanese) after I have paid for and got exchange documents but before I have validated the Rail Pass?