Tokyo to Kawazu

Hello, I am trying to figure out the most cost effective way to travel from Tokyo (Nippori station) to Kawazu to attend the Sakura festival.
I really have trouble understanding the passes etc. I can't find the prices for a round trip to work out which would be more cost effective.
Whilst in Japan we plan to go to Kawazu, and Hakone. Both from Nippori.
Can someone help?

Which date?

No enough search at Google MAP or HyperDia?
https://goo.gl/maps/T7bZAgbvEeD2
If you want to go cheaply even if it takes longer time,
use HyperDia as no SHINKANSEN or SHIKANSEN and Limited Express both like this.
http://www.hyperdia.com/en/cgi/en/search.html?dep_node=NIPPORI&arv_nod...

If you do not visit Hakone, JR-East provides a roundtrip discount ticket,
http://www.jreast.co.jp/tickets/info.aspx?GoodsCd=2216
but if you go to both inevitably in a day by all means there is no discount.

So tell us the exact travel date and where will you go in Hakone.
http://www.hakonenavi.jp/english/traffic/rout_map/

Thank you SimpsonH.
I didn't know about Hyperdia, that'll help. I've tried google but I've found it quite confusing. (I have dyslexia, so it's been difficult for me trying to organise the transfers etc, and figure out which line I should be on). And that return ticket is very useful, I couldn't find it on the English version of the site. It looks like you just go into the ticket office and ask for it, is that correct?
We plan to go on either the 28th of february, or the 1st of march We're avoiding the weekend as I think it'll be very busy at the weekend.

I can't see an edit, so sorry for double posting.

As for Hakone, it doesn't need to be on the same day.
My partner and I wanted to visit the hotsprings, and to see Owakudani as well as the temple.
We haven't set a day for then, but again would avoid the weekend so it wouldn't be so busy.