if you are in Hakone for only one day. I recommend to get to Togedai and join the cruise to cross the lake. the boats are pirate ship and the inside looks amazing. it's quite big, there are 2 inside decks and 2 outside decks. Price is 1050¥ or add 500 for the first class. but honestly, the second class is very well too. it takes about 30 minutes to cross the lake and choose between 2 final destinations to finish your tour. you can see mount Fuji from the second half of the lake.