Kurobe gorge train tickets

Hi ;
We are planing to visit Kurobe Gorge in August, and since it's the pick season, I try to book the tickets ahead.
I plan to get off at each station and have short travel and take some pictures.
I understand from the site that in this case I can book the tickets only to the first station, and then to buy the tickets to the other stations there.
I don't want to be left without tickets back to Unazuki station but I don't know how long is the approximate travel time with all the stations.
Should I book the tickets from Keyakidaira station for 3 hours after we start the travel from Unazuki station? Or 3 hours is not enough for the total trip, and I should book the tickets back for a longer interval between inbound and outbound?

Kurobe gorge railway is 20 km Long,From unazuki to keyakidaira 1 way=1980yen,80min

Best for you to book a one-way ticket to Keyakidaira station, and take your time visiting each station on your way back. We visited those places a few years ago taking the first train from Unazuki Station and returning early in the evening. So if you are planning to spend only 3 hours on the visit, you might be doing the " amazing race".

Kurobe gorge railway
You can buy 1 day pass =5100 yen
This pass valid from may 10 to nov 23, 2023