what pass should i buy?

Good day forum hosts and friends, It is my first time travelling to japan and I would like to know what pass should i buy with the following Itinerary.

day 1 Narita airport to Tokyo, stay in tokyo 1 night
day 2 Early morning travel to yamagata by train to visit the snow giants at zao onsen and then travel to Oishida to take bus to Ginzan then back to yamagata again to stay a night
day 3 travel from yamagata back to tokyo.
day 4 travel to Mount Fuji by train for a day trip at mount fuji then after that travel back to tokyo
Day 5 and Day 6 spend at Tokyo
day 7 back to home country

What pass should i buy to save travelling costs. Please help me:)
Thank you all in advance for your time and expertise.