Tokyo Metro and the Bureau of Transportation announced new 24, 48 and 72 hour tickets for Tokyo subway. The new tickets will replace the current one, two and three day tickets on March 26, 2016. The tickets will be valid on all Tokyo Metro and Toei Subway lines.

New Tokyo Subway 24, 48 and 72-hour tickets
The pricing remains the same as the current one, two and three day tickets:
“Tokyo Subway 24-hour Ticket” valid for 24 hours (800 yen)
“Tokyo Subway 48-hour Ticket” valid for 48 hours (1,200 yen)
“Tokyo Subway 72-hour Ticket” valid for 72 hours (1,500 yen)
The ticket validity period starts from the first time it is used. For example, if you first use a 24-hour ticket at 5:00 pm, you can continue to use it until 5:00 pm the following day.
The new ticket will be made available to foreign and Japanese travelers visiting Tokyo from outside the greater Tokyo area.
The new 24, 48 and 72 hour tickets for Tokyo subway lines can be purchased at Narita and Haneda Airports, local and overseas travel agencies, some Bic Camera and Sofmap locations within Tokyo, HIS Tourist Information Center and select hotels within Tokyo.