Trip from FEB 16 to MAR 2

I am asking this question because I want a honest answer. I am traveling with my girlfriend next year and we can not decide which rail pass is better for our trip. Below is our itinerary:

Arriving to Narita FEB 16th

Leaving to Kyoto FEB 21st

Kyoto to Osaka (one day trip) FEB 24th

Traveling to Nagano, Kusatsu Onsen FEB 26 (returning to Tokyo and then traveling to Kusatsu onsen from there) I think is faster that way.

Tokyo to Narita airport MAR 2nd

Please advice on buying a 14 day raillpass or a 7 would be enough. Thanks.