Which pass should I buy

Hey,

Now i'm going to be coming to Japan for a conference from 18th-23rd March, in Tokyo. Post that me and a friend of mine plan to travel around Japan. Our itinerary is broadly as follows.

23-27 March: Tokyo - Plan to Visit Hakone, Yokohama, and Tokyo Attractions during these days.
27th March : Osaka
27th-29th March: Kyoto
29th March: Nara
30th March: Takayama
31st March: Kobe
1st April: Hiroshima
2-5th April : Osaka and flying out

Now i heard about the PASMO cards. Is its useful to travel the trains from Tokyo/Kyoto/Osaka to the various places?
And could i get an estimate on the fares of the Reserved and Unreserved seats on the rail.

Thank you for reading through the post and Thank You again for helping me out.

Have a beautiful day ahead.

Varad