False advertising - you don't actually get these speeds.
Before you guys get all wound up about how expensive US broadband is blah blah blah you should know that US ISPs are a lot faster than Japanese ones. North American websites load MUCH faster if you live in the US and speeds are better than what you got if you lived in Japan.
Speed test results from a So-Net 100mbps (supposedly) connection:
To Tokyo - 24/20mbps
To Los Angeles - 16/5mbps
To New York - 3.5/7.75mbps first test, 10/4mbps second test
To London - 3/5mbps
To Germany - 9/3mbps
Japanese customers on the 2GBPS (supposedly) plan will probably get something like 100mbps domestically and similar to the above for international. You can call it 2GBPS all you want but when your international uplinks are saturated and only allow cable-modem speeds the connection speed is completely pointless.