Tokyo is well known for its very efficient public transportation network. Trains and buses all run frequently and punctually.
In central Tokyo, railways (including underground lines) are operated by a few companies, such as JR (Japan Railway East), Tokyo Metro, Toei, and so on. Lines operated by different companies may be seamlessly connected (i.e. a train runs through two or more lines without any transfers). Please note that, even though the following railway maps provided the above-mentioned companies may not show lines operated by other companies, they are actually well connected to each other. On top of that, there are buses running and connecting railway/subway stations.
But it must also be noted that, especially at big stations like Shinjuku, Shibuya and Ikebukuro, transferring from one line to another requires a lot of effort.
You will find purchasing an IC card (in Tokyo, either Suica or Pasmo – either is fine) useful. You can use it for all the train and bus lines, as well as any convenience stores, and often even vending machines.
Should you have any inquiries, please contact: firstname.lastname@example.org