JR Pass or Seishun 18 Kippu?

Hello, I have a question regarding my planned vacation in Japan. I was planning on visiting Tokyo, Kyoto and Foukaka but since I'm a poor student from Sweden transportation costs are somewhat troublesome.

I was planning on visiting these cities in this order (I arrive at Narita Airport on the 29th):

1. Kyoto, 29th of March to 2nd of April
2. Tokyo, 2nd of April to 5th (the weekend)
3. Foukaka, 5th of April to 9th

due to my friend in Tokyo being unable to take days off from work.

So, either I buy a JR Pass for 14 days so I can go on the shinkansen to all three cities (is that correct by the way? I may have misunderstood).
Or I buy the Seishun 18 Kippu and go on slower trains. If I buy the Seishun 18 Kippu, can I still go to all three cities? Or will the travel times be too long for it to be effective?

The order you visit the cities is very ineffective in terms of distance traveled. You will be traveling very long distances. Therefore, a Seishun 18 Kippu is out of question. You would be spending half of your holidyas on board of local trains.

I know, it's really the most inefficient way of visiting these cities. My problem is that one of my very good friends in Tokyo can't take days off from work, so I have to visit him during the weekend (which is a problem when I arrive on a Monday).

But I shall heed your advice since the time I'll be spending on trains is going to be waaay too long.