Before going to Japan, it is a must to do your due diligence on all the expenses that might occur during your stay. And one of the biggest issue would be transportation cost.
For those who will be staying around Japan, I would recommend using Tokyo Metro Subway that covers both Tokyo Metro and Toei Subway lines. These are the 2 major subway operators in Tokyo. Tokyo Metro offers 3 types of ticket mainly 24, 48 and 72 hours ticket of unlimited ride on all Tokyo Metro and Toei Subway lines.
Price wise, there is only 2 category which is adult and kids.
Tokyo Subway 24-hour Ticket – Adult: 800 yen, Child: 400 yen
Tokyo Subway 48-hour Ticket – Adult: 1,200 yen, Child: 600 yen
Tokyo Subway 72-hour Ticket – Adult: 1,500 yen, Child: 750 yen
**Note that the validity hour starts from your first use. Example, Friday 3pm first use, ends at Saturday 3pm for 24-hour ticket.
Based on the above price, the best would be the 72-hour ticket! It's just 500/yen a day! A trip back and forth (based on the cheapest price, 160/yen one-way) easily cost 380/yen which is more than half of the price. All you need to do is travel to 2-3 places and it makes your ticket worth it's value!
Example, your trip would be 9 days. Just buy 72-hours ticket X 3 piece and you'll all good to travel around Tokyo!
You may also download the subway map with variety language from here.
And you can also download the subway app for iOS and android here or here. This will be handy when you are travelling around Tokyo as it provides the number of stops and cost estimate for your journey!
You may also plan your journey ahead using the Transfer Planner and Fare Calculation here.
This planner provides you the cost estimate and also the stations that you need to hop in in order to reach your destination. All you need to do is fill in the "FROM" and "TO" and click search! You may also insert the start time of your journey (optional) to have a better accurate on the estimate arrival.
That's all for now! More information will be posted time to time! Just follow my profile! Do ask if you have any uncertainties!