Yes, you can do both Hakone and Mt. Fuji in one day, but it is a very fast-paced itinerary. Most travelers in 2026 take a guided "combination tour" departing from Shinjuku, Tokyo. This typically involves a morning visit to the Fuji 5th Station (halfway up the mountain) followed by an afternoon in Hakone for a Lake Ashi pirate ship cruise and a ride on the Hakone Ropeway over the volcanic Owakudani valley. If you go independently using the "Hakone Free Pass," it requires careful planning of train and bus schedules. While you'll see the highlights, you won't have time for a relaxing soak in an onsen (hot spring). For a more "Zen" experience, many people prefer to do just one or the other, but if you have only one day and want the "Big Two" photos, the combo-day is totally doable.