Highway Bus from Kanazawa to Shirakawa-go

Hi,

I read from http://www.hokutetsu.co.jp/en/en_highway-takayama, as well as from https://www.japan-guide.com/bus/shirakawago.html ......but i am confused on how to read the timetable between Kanazawa and Shirakawa-go.

I will be staying in Kanazawa city. I am going there in late May on a WEEKDAY. I noted from April onwards, the highway bus from Kanazawa will stop at Gokayama, before going to Shirakawa-go. Is it possible for me to book the highway bus such that it will go from :

Kanazawa > Gokayama > Shirakawa-go > Back to Kanazawa ?

Will I be booking a round trip, or it will be 4 bus trips altogether ? i am confused how to read the arrival and departure times from the 2 time tables stated in above websites.

How long will this whole trip be, if you estimate the time i need at each stop, to tour the place ?
Can I just book the bus trips at Kanazawa station the day before ? Because i noted if i book online it cannot be round trip.

Thank you.

The timetable of the Japan Guide is displayed vertically as the timetable of the Nohi Bus.
English
https://www.nouhibus.co.jp/highwaybus/kanazawa_en/
Japanese
https://www.nouhibus.co.jp/highwaybus/kanazawa/
Another link is the timetable of the Hokuriku Tetsudo(Hokuriku Rail road) Bus. (The bus company is different.) This is a timetable on the side.
http://www.hokutetsu.co.jp/en/en_highway-takayama
However, I think the content is the same depending on whether the table is displayed horizontally or vertically.
In both tables, the timetable of the two bus companies is mixed and displayed.
It seems that you can not make a reservation in May yet, but I think you can make a reservation from here one or two months ago.
https://japanbusonline.com/en#