Prepaid Transportation Cards
SUICA
SUICA is a loadable IC card that is mainly used to pay fares on trains and buses.
It can also be used in some other stores near the station such as convenience stores.
It is much faster and is slightly cheaper than buying a ticket each time you ride.
You can buy them on virtually any stations for 500 Yen.
PASMO
PASMO is another loadable IC card that is issued by a different company.
It functions almost exactly the same as SUICA, but the main difference is in the way monetary points get add up when being used.