JR All Shikoku Pass question

Hi.

Am planning to visit Shikoku soon. I see that the JR Shikoku pass is only valid for 5 days at most. I am planning to stay about 10 days. Does it make sense for me to buy two passes instead? Activate one when I reach from Okayama, once pass 5 days, activate the second pass.

Can it work that way?

Thanks.

As usual, whether or not it makes sense depends on the cost of your trips vs the cost of the pass...

Use Jorudan or Hypermedia and find the cost for your estimated itinerary.

http://www.jorudan.co.jp/english/

http://www.hyperdia.com

I am planning to stay about 10 days.

Confirm your itinerary before getting 2 passes.
I also spent 10 days last year, and bought 1 All Shikoku Pass only . Some sections of my travel needed buses / no trains ; other short distances just purchased day tickets, and 2 onsens we were staying provided complimentary shuttles.

Remember that there is quite a bit to see up North of Shikuku which is relatively cheap to travel around. It may be possible to only buy 1 pass, depending on your schedule....

I'm thinking of going around the island.. but not too sure if it's doable in 10 days. Tokushima, Kochi, Uwajima, Matsuyama and Kotohira.

Again, it depends on what you want to see.
As far as using public transportation goes, Kagawa, Kochi, and Ehime are pretty interesting. Tokushima not as much, and Tokushima City you can pretty much skip entirely 51 weeks of the year. Takamatsu seemed to be the most interesting city overall.
One of the biggest challenges is that transportation is really sloooow. I went from Kochi City to Uwajima and that took forever. I really was the only one on the "one man" train.
The real delight of the island was Kotohira - it was a marvelous experience and the trip up was more of an adventure than the beautiful view from the top:
https://www.youtube.com/watch?v=ley9rVIewoQ
That said, it is not for the out of shape or arthritic. Come to think of it, the Taga Shrine in Uwajima is not someplace you'd want to go with your parents either:
https://www.youtube.com/watch?v=g0WcmpSQ7S0
But one of the most beautiful places was in Takamatsu - the Ritsurin Garden was something everyone should go and enjoy - just incredibly beautiful.
https://www.youtube.com/watch?v=afx-Ju52FiY
The Takamatsu castle remains were not that exciting however. If you want to see something better, Matsuyama offers something much better. Uwajima's castle is quaint but still enjoyable. Dogo onsen in Matsuyama is also one of Japan's oldest.