I would say the most important piece of equipment is good hiking boots. I lugged my hiking boots with me all over Japan in my suitcase and I'm really glad I did. My friend that was with me wasn't prepared and only had his sneakers. He slipped a lot on the way down. I didn't bring much gear or equipment otherwise. The only thing I wish I had done differently was either bring a waterproof cover for my backpack or had everything in waterproof plastic bags inside the pack. Even if it rains for 10 minutes everything will get wet. The weather can change rapidly and drastically. Like the other poster wrote, constantly shedding and then putting clothes back on, It got cold at night so you wan't to make sure you have something dry. Extra socks and also a decent head lamp to see in the dark is highly recommended. Lots of water too. Lots of gear not really necessary. Just dry, warm, hydrated and comfortable. You really don't want to carry more than you have to. Have fun!

Mt. Fuji with snow on the summit is seen from mid sep to early July. Your profile pic seems to be taken around May. But it’s too small to recognize correctly on my iPhone;)

Thank you

No lo sé. Sorry

If you mean time of year, after the rainy season is over (~July 21). Unfortunately, that’s also when the school year ends so it’s more crowded with families.

We were lucky when we were there, as every now and then the clouds moved and the mountain became visible enough to photograph, but it was not brilliant. Most of the time it was overcast. We were in Japan for the "sakura", or cherry blossom time in April.

I like to just buy the ticket when I’m there at the airport/train station etc. This way if there are any hiccups I can be flexible and don’t have to worry.

I would not recommend starting from 5th station in the afternoon as it’s too late. We arrived at 5thstation about 10 in the morning and we left from Tokyo, but collected others from Gotemba station which is close to Hakone. You need to give yourself plenty of time to get up the mountain and take rest breaks along the way. We arrived at one of the 8th stations at around 4.30 in the afternoon and we were in the faster group. The slower group did not make it until around 6 and its getting dark.