Tokyo Metro has more coverage and goes to more places then JR, sometimes you might have to make one extra transfer other times you don't.

first, buy 2 day pass 980 yen and pay for additional ticket (about 170 yen) from Kuramae to asakusa or ueno or other station that connect to Tokyo Metro subway
e.g. ticket from Kuramae to Asakusa ( 170 yen) + use 2 day pass ( 490 yen/day) + ticket from Asakusa back to Kuramae (170 yen) = 170+490+170 = 830 yen/day

You don't go to asakusa everytime that you travel. you can go to any station that connect to Tokyo metro subway.
e.g.Nihombashi station, you pay 170 yen take train from Kuramae to Nihombashi and use your pass

second , you can buy Common One-day Ticket for Tokyo Metro & Toei Subway
http://www.tokyometro.jp/global/en/ticket/oneday.html#o...

Kuramae is on Toei Subway.you can use this pass on any Tokyo Metro subway or Toei subway.It's 1000 yen/day