Nagoya/Osaka Takayama Tokyo

Hi All, We are in the midst of planning our trip to Japan from 1st to 13th Dec. We want to explore Osaka, Takayama (1d), Shirakawa (1d) and Tokyo. Not sure which route to start from. Appreciate if you can advise the correct route to plan. Do you need a JR pass?

Option 1: From SIN to Nagoya to Takayama / Shirakawa to Osaka to Tokyo

Option 2: From SIN to Osaka to Takayama / Shirawaka to Tokyo

Option 3: From SIN to Tokyo to Takayama / Shirawaka to Osaka

Thank you so much.

Regards,
Serene

Here are some trials.

Ex 1: Nagoya - Shirakawa - Takayama - Osaka - Tokyo
A 3900 yen, Nagoya 800-1041 Shirakawa http://www.gifubus.co.jp/highway/shirakawa/tt_shirakawago.pdf
B 2470, Shirakawa 643-750 Takayama (backtracking A) https://www.nouhibus.co.jp/highwaybus/toyama/
C 4700, Takayama 700-1237 Namba (backtracking B & A) https://www.nouhibus.co.jp/highwaybus/osaka/
D 13620, ShinOsaka 600-823 Tokyo, JR
A+B+C+D: 24690

Ex 2: Osaka - Shirakawa - Takayama - Tokyo
A 7130, Osaka 630-913 Kanazawa, JR
B 1850, Kanazawa 940-1105 Shirakawa https://www.nouhibus.co.jp/highwaybus/toyama/
C 2470, Shirakawa 643-750 Takayama https://www.nouhibus.co.jp/highwaybus/toyama/
D 6690, Takayama 630-1200 Shinjuku https://www.nouhibus.co.jp/highwaybus/shinjuku/
A+B+C+D: 18140

Ex 3: Tokyo - Takayama - Shirakawa - Osaka
A 6690, Shinjuku 705-1235 Takayama https://www.nouhibus.co.jp/highwaybus/shinjuku/
B 2470, Takayama 750-840 Shirakawa https://www.nouhibus.co.jp/highwaybus/toyama/
C 1850, Shirakawa 850-1005 Kanazawa https://www.nouhibus.co.jp/highwaybus/toyama/
D 7130, Kanazawa 1056-1337 Osaka, JR
A+B+C+D: 18140

Ex 1 costs most with backtracking. I would drop this. Ex 2 has more time in Takayama than Ex3. I would take this. With Ex 2, it might be better to stay in Kanazawa.