Otsuki Station - What time do they open?

Hello! My sister and I are going to the Fuji Five Lakes area and we�fre thinking about buying the Fujisan Fujigoko Passport. We would like to use it starting at Otsuki Station and then to move around with the buses (for example out to the Bat Cave, Iyashi no Sato, Fujiyoshida Sengen Shrine, sakura around Kawaguchiko, etc.) and back to Otsuki that evening.

At what time do they open Otsuki Station to be able to buy this ticket? We were hoping to start very early and visit the Chureito Pagoda around 7-8am, being at Iyashi no Sato soon after opening time. We have many things to do that day.

The ticket counter of Fujikyu Otsuki Station opens at 6am, but I am not 100% sure whether this is where you can buy that passport:
http://www.fujikyu-railway.jp/station/timetable.php

Accoring to https://www.japan-guide.com/e/e6905.html

"The pass is sold at the Fujikyu ticket counters at Kawaguchiko Station, Fujisan Station, Mishima Station, Shin-Fuji Station, Fujinomiya Station, Gotemba Station and the Asashigaoka/Yamanakako bus stop. "

Since the OP is starting from Otsuki station, the pass should be the version including the Fujikyu railway from Otsuki to Kawaguchiko. This version is sold also at Fujikyu railway's Otsuki station.

http://www.fujikyu-railway.jp/ticket/ticket17.php