Japan Railway has recently announced that they will begin offering free Wi-Fi on all Shinkansen lines during the current fiscal year that ends in March.
Despite strong demand from foreign visitors, only a limited number of bullet trains have wireless Internet access at present.
The new service will be available on all the following trains, including Tokaido Shinkansen which many foreigners use to travel between Tokyo and Kyoto / Shin-Osaka.
Akita Shinkansen - by May 2019
Hokuriku Shinkansen - by September 2019
Tokaido Shinkansen - by March 2020
Sanyo Shinkansen - by March 2020
Kyushu Shinkansen - by March 2020
Yamagata Shinkansen - by March 2020
Japan Railway will also start to offer free Wi-Fi on more trains on the Hokkaido, Tohoku and Joetsu Shinkansen lines.