It seems you need more research based on reliable sources....
Some basic conditions for your trips are not yet given: dates, your airports, your timeline, your major destinations, the number of the travelers.
Tokyo - Kyoto - Osaka Or Tokyo - Osaka-Kyoto- Osaka. Will you fly into Narita [NRT] | Tokyo Haneda [HND] and fly out from Kansai [KIX]?
Then, a Japan Rail Pass would not pay off.
You can choose a package for a Shinkansen train ride without seat reservation at a discount price, which may be a good deal when you leave Tokyo for Kyoto | Shin-Osaka on the 7th or later day of May 2018, i.e. outside a high tourist season.
The Shinkansen goes not via Osaka Station; the only Shinkansen station in Osaka City is Shin-Osaka Station.
What should I buy There is no pass which you "should" buy; you
can buy some passes, on certain criteria.
the JR pass or Pasmo pass for every place? A PASMO card is not a pass.
Suica and PASMO are fare collection systems which work with IC transportation cards such as Suica cards and PASMO cards.
These IC cards basically do not give you discounts on railway fares, neither do they allow you to have train rides for unlimited times.
DanJpan:
Pasmo doesn't work on JR lines That is not collect.
Suica cards and PASMO cards have been usable completely in the same way on both JR and non-JR lines, since PASMO system got started, following Suica.
You cannot return a Suica | PASMO card for a refund in Kansai Region.
The e-money stored on the card will be effective for 10 years after the card is last used correctly.
(A card which has not been used for a long time might be once rejected by a machine for a further inspection by the railway staff.)
- IC cards in Japan
https://www.japan-guide.com/e/e2359_003.html
