Three Star Route pass

Does anyone know about the Three Star Route pass to travel between Matsumoto-Takayama-Shirakawa-go and Kanazawa.

How do we book tickets and from where?

Hi. It seems like there's no English information about the three stars ticket. Maybe you can google translate their Japanese website.
http://www.hokutetsu.co.jp/highway-bus/mitsuboshi-root-kip

You can buy the tickets at the following locations.
- Hokutetsu station center (next to the bus stop 1 of the Kanazawa station east bus terminal)
-Matsumoto bus terminal (at the Alpico transportation company)

Hope this helps.

https://www.nouhibus.co.jp/english/ticket/

This is in English.

Note that this is not a pass but ticket: You can ride one section only once and can't backtrack.

https://option-ticket.mitsuboshi-kaidou.com

Not so clear about how to book tickets for this.

It seems to be two types of Three Star Route tickets.

Three Star Route Option Ticket sold by JR East. 5500 yen.

https://www.jreast.co.jp/e/pdf/press_20190704_e.pdf

This is for foreign visitors only.

Sold at: The following JR East ticket counters
JR EAST Travel Service Center (Tokyo Station, Shinjuku Station, Shibuya Station, Ikebukuro Station, Ueno Station, Hamamatsucho Station, Tokyo Monorail Haneda Airport International Terminal Station, Narita Airport Terminal 1 Station, Narita Airport Terminal 2・3 Station)
JR Ticket Offices (Midori-no-madoguchi) (Narita Airport Terminal 1 Station, Narita Airport Terminal 2・3 Station, Matsumoto Station)
Travel Service Center (View Plaza) (Nagano Station, Matsumoto Station)

Three Star Route Ticket sold by Alpico Bus and Nohi bus. 6000 yen.
Alpico bus site (I believe Nohi bus sells the same ticket).

https://www.alpico.co.jp/en/three-star/

Available at
Matsumoto Bus Terminal 4:40 – 21:00 Credit cards accepted
Hokutetsu Kanazawa Ekimae Center (Kanazawa Type only) 7:00 – 20:00 Credit cards accepted
Toyama Chitetsu Ticket Center (Toyama Type only) 7:00 – 19:00 Credit cards accepted

Japanese locals also can buy it.