My itinerary as follows, from calculator noted 7 days japan rail or takayama regional is ok. But i'll be going to kawaguchiko & shirakawago not sure which is better.
8/12 - narita to shinjuku
11/2 - Shinjuku to kawaguchiko
13/12 - kawaguchiko to Kyoto
15/12 - kyoto to shirakawago (day trip)
15/12 - shirakawago to Kyoto
16/12 - Kyoto to Osaka
18/12 - Osaka to kansai airport

