As you may know, Japan is famous for its bullet train or shinkansen (新幹線, which literally means “new trunk line”). These trains can now run at speeds up to 320km/hour (200mph). When shinkansen service first started in 1964, the bullet trains only ran at about 210km/hour (130mph) on one line connecting Tokyo and Osaka – but even this speed was much faster than most other trains. Today trains that run this fast or faster already connect most major cities on the islands of Honshū (Japan’s Main Island) and Kyūshū (South Island). Beginning on 3/26/16 the first shinkansen will travel between Honshū and Hokkaidō (North Island), and those islands will be connected through a tunnel.
A short video showing shinkansen trains in operation network is here.