Whether to buy JR Pass for my 15 day itinerary

Hello!

I am travelling to Japan in Dec, for 15 days. I've been reading about the transport but I get confused due to too many available options. I'm wondering if you could help advise with the below itinerary, will JR pass be sufficient or needed at all

9-Dec-2022 Vietnam-Osaka
10-Dec-2022 Osaka - Nara - Osaka
11-Dec-2022 Osaka - Kyoto
12-Dec-2022 Kyoto
13-Dec-2022 Kyoto
14-Dec-2022 Kyoto to Shirakawago
15-Dec-2022 Shirakawago - Takayama
16-Dec-2022 Takayama
17-Dec-2022 Takayama - Sapporo (via Nagoya)
18-Dec-2022 Saporo
19-Dec-2022 Saporo
20-Dec-2022 Saporo-Tokyo
21-Dec-2022 Tokyo
22-Dec-2022 Tokyo - Mt Fuji - Hakone - Tokyo
23-Dec-2022 Tokyo
24-Dec-2022 Tokyo - Vietnam

It would be great if you could recommend on the transport options