Hi, accoding to Fujikyuko Bus Website,
the local bus runs from 4th of April to 30th of June. http://bus-en.fujikyu.co.jp/
Check the details from the website.
This website looks a bit complicated to find some information,
so I reccomend you to make sure if they have the bus on your travel day and how to get there.
There is phone number in the website.
I also found Japan Guide website below. http://www.japan-guide.com/bus/fuji.html
There are some shrines, gift shops, cafe/restaurant, lodge, and some activities on the 5th station.