That vacancy info service already overed/I—¹ on last year Dec.
http://www.web-sanin.co.jp/sight/time/"JR CYBER STATION" provided only up route train for Tokyo/“Œ‹ž "nobi-nobe seat" like this.
http://i.imgsafe.org/307248b9ef.jpgBut no EN menu and no online reservation system.
Just you can see vacancy info still left(no excat left number) or not.
http://www.jr.cyberstation.ne.jp/vacancy/Vacancy.htmlhow to :
‚¨æ‚è‚É‚È‚é—ñŽÔ(Shinkansen or not) : Ý—ˆü—ñŽÔ(conventnioal line's train)
æŽÔ‰w(dep)E~ŽÔ‰w(arr)
Izumoshi : o‰_Žs (Izumo)
Takamatsu : ‚¼ (Seto)
Okayama : ‰ªŽR (Izumo/Seto)
Osaka : ‘åã (Izumo/Seto)
Resered seat sales just one month before 10:00am(JST).
Fri,Sat,Sun,last night of National holidays,
also super busy days Golden week,Obon,Silver week
and around year end/new year day 99.999% you can't.
So only regular weekday (except Fri) may possible but no exact.
No online reaservation system by form/e-mail.
Only by int'l call(81+) possible. (as purchasing by credit card)
https://www.jr-odekake.net/goyoyaku/phone/http://www.japan-guide.com/e/e2223_how.htmlBut ticket reciving at JR West or Shikoku major stn
or delivery order to yr hotel(or) in Japan but risky as timeline if far and.
Japan Rail Pass holder have to refund at stn ticket office until train dep for exchanging nobi-nobi seat.
https://www.westjr.co.jp/global/en/howto/ticket_02.html#fqtopQ: What kinds of credit cards do you accept?
A: We accept Visa, MasterCard, American Express, UC, DC, JCB, Diners Club, CF, UFJ, and MUFG CARD.
Ticket delivery fee :
http://www.jr-odekake.net/goyoyaku/phone/purchase_delivery.html