8 days itinerary in Tokyo

Hi all, please suggest your opinions.

We plan to visit Tokyo (first time to Japan) on 31/3/15 & will stay in Toyoko Inn Shinagawa Hatanodai-eki Minami-guchi for 7 nights. Itinerary as follow:
day 1 - Shinjuku
day 2 - Mt Fuji
day 3 - Disney Sea
day 4 - Yokohama
day 5 - Yokohama
day 6 - Akihabara, Asakusa
day 7 - Tsukiji, Shiodome, Odaiba

As from hyperdia info, we need to take from Hatanodai station (Tokyu Ikegami line) to Gotanda (JR Yamanote) to Shinagawa then can go to other places like Shinjuku, Ueno, Akihabara (JR Yamanote line) etc. May i know:
1) what is the suitable day pass to purchase (Metro&Toei or JR or others)? Is it i need to pay 300 yen first (from Hatanodai to Shinagawa), then from Shinagawa i use the JR Tokunai pass to other places?

Not really a pass but you can load up a Suica or Pasmo IC card and just tap as you go in and around Tokyo.

Hope this helps!

Have fun!

Thank you Koohii2wii.

Is it cheaper if using Suica/Pasmo ic card? As we are first time to Tokyo, sometimes we may miss the stations when taking train or metro, so we think of buying a day pass would be cheaper (unlimited rides), what do you think?

It is cheaper if you use the IC card, but don't expect tremendous savings. If I recall, a trip with a paper ticket will cost 3 yen less on the IC card or something like that.

Thank you John for your suggestion, arigato!