Can I book seats for oversized baggage on the Kodama Train?
The Kodama Train on the Tokaido Shinkansen runs between Tokyo and Shin-Osaka and caters largely to Japanese commuters rather than people traveling for leisure, much like the many express lines that operate throughout the country, so typically, all the ordinary cars for this train are non-reserved in order to accommodate those traveling more frequently who wish for a more streamlined process. But in regard to the new policies, one car on many Kodama trains will have reserved seats and a section for passengers with larger baggage. However, this is not the case for all Kodama trains, so be sure to check the Sanyo Shinkansen and Kyushu Shinkansen websites to confirm. For these trains, note that it may be necessary to book a seat in the more luxury-level and spacious Green Car in order to accommodate large suitcases, as opposed to the more plentiful and accessible ordinary cars.
What if I need help with boarding and getting off the train?
Naturally, with oversized baggage, boarding the Shinkansen, disembarking the Shinkansen, and general movement become a bit more hindered. In principle, the new policies in regard to oversized baggage were designed to further ease travel for riders, so bullet train and station staff will do everything in their power to promote an easier flow when traveling and guide you throughout the process. If your large baggage is difficult to bring onto the train and/or put into the designated area on your own, alert train or station staff, who will assist you with handling your luggage, though staff will have other duties to tend to while the train is operating, so there may be a need to wait if staff are busy.
AloJapan.com