I booked this hostel at the last minute, because I wanted to add an extra night to my winter vacation trip. The first couple nights I had stayed at a slightly more expensive hotel near Kawaguchiko Station, just a few stops away on the Fujikyuko Line.
Compared to that hotel, Hostel Mt. Fuji actually had better wi-fi service, and a stronger shower. It was so refreshing to be able to jump in the shower after a day of hiking and not have to deal with low water pressure.
I was also extremely lucky in that I was the only guest in the hostel that night. Even though I had only paid 3,000 yen for one bunk in a 9-bed dormitory, I ended up having the place all to myself. So the privacy was also a plus.
This is a small hostel, just recently opened, with I think only one or two dormitories. From the road, it almost looks like a house. But everything in the building seemed new and clean.
The owner, Machiko, spoke English well, and was extremely helpful during my stay. When I made my last-minute booking, I did not realize the hostel was so close to Chureito Pagoda, with its famous view of Mount Fuji. But Machiko-san gave me a map and directions for how to get there. (It's only about a 15-minute walk.) In the morning, she offered me coffee, and as a "winter service," provided me with bread and a boiled egg for breakfast.
Overall, my experience at Hostel Mt. Fuji, while highly subjective, was very good, and I would certainly consider staying there again.