what is better JR pass or individual ticket to secure seat

hi ,

we are traveling to Japan on the 3rd of October - getting to Tokyo on the 4th October
what would be preferable - JR Pass or individual tickets - and JR pass indeed how can ensure my chance to reserve desired seats?

plan is:

7th October- Tokyo- Kawaguchiko

8th October- Kawaguchiko-Hakone

9th October- Hakone-Odwara-Kyoto ( need to be in Kyoto around 12:00- Hikari 637)

10th October- Kyoto - Himeji- Osaka

11th October - possible Osaka - Okayama- Osaka

12th October- Osaka-Nara-( Osaka) -Tokyo

13th - Tokyo -Tokyo Narita

many thanks