By Subway

The subway is available in Tokyo, Fukuoka, Kobe, Kyoto, Nagoya, Osaka, Sapporo, Sendai and Yokohama. Like with electric trains, its tickets are sold from ticket machines. Few stations have English-written diagrams with prices. When in doubt about the price, buy the cheapest ticket to pay the remainder on arrival.
Buying usual tickets by packages of 11-14 saves 10-20% on fees. You can use them both for yourself and as a group.
See also Pre-Paid Cards in Kanto region and Kansai region.