which day i shall activate my JR pass (7 days)

Hi Vivien,

The JRPass is great if you do multiple long distance trips or visit different areas in Japan. For instance a 7 day JR Pass is about the same price as a return Osaka/Kyoto - Tokyo. However your long distance travel is limited to one way Tokyo - Kyoto, so I do think that it would be best just to buy normal tickets for your travel.

I would recommend getting a [Suica + NEX] package for your travel from Narita Airport to Tokyo. This will give you a greatly discounted ticket on the Narita Express and a also gives you a prepaid travel card (Suica card) which you can use to pay for your travel in and around Tokyo/Osaka.

I hope this helps!
Daniel