1) Get to Shinjuku and go here (street view and website)

2) If you are planning a day trip, go early. I went for 7 and, from the handy timetable found here, you can choose which bus you are going to take there and back.

3) By a ticket. You can book online if you like, but out of season and Japanese national holidays I doubt you’ll find the bus full. Buy the ticket from the ticket office, (1700yen one way, you can’t buy a return you’ll be told, you buy it once there) and get on the bus.

4) Once at Kawaguchiko, follow the signs and go for a walk. The path around the lake lasts about 15km, and stops about half way so you have to follow the road the rest. The reason it stops is the view of Fuji goes behind a smaller mountain, but you are half way round the lake already so you might as well keep going. If you feel lazy there are buses that go around the lakes area. You could go to one of the other lakes if you have time, although the views are no more special, although with maybe less hotels, unless you are willing to travel to Yamanaka lake to the south.

5) Get a bite to eat somewhere after the long walk. There is nothing much around the station but a short walk away are some chain places.

6) Go home. Last buses are at 8ish although that is after an hour wait from the previous one. Also, it gets dark and cold come 5pm so probably best to leave by then anyway. The bus back wasn’t busy, although everyone did pile on once it stopped at at Mt Fuji funland

If you want other ideas on viewing Mt. Fuji, I was mulling over this page for a while. With limited time and the potential of getting lost, I chose the easy option, although climbing a mountain near Lake Yamanaka and watching the sunset did pass my mind, if I thought it wouldn’t die trying to get back in the dark.

More information on travel, including trains (more expensive as far as I can tell) can be found here.