As Sue M. noted in another discussion, Tauck has upgraded the activity and pace for Essence of Japan from level 2 to level 3. These are described as:
Activity: Active components such as hiking, bicycling and walking longer distances may be included and hills or uneven terrain may be encountered on several days. Guests should be able to walk 2-3 miles and stand for long periods of time with no difficulty.
Pace: Often robust - may include long days, active sightseeing, early starts, evening activities, significant travel times.
The only thing listed above that this tour doesn't include is bicycling. This is a physically active itinerary. You not only need to be able to walk 2-3 miles, but you need to be able to walk 2-3 miles every single day for two weeks straight. According to my pedometer, the shortest total distance we walked in one day was 2 1/2 miles and the longest was 7 miles. We averaged 5 miles of walking per day over the entire tour.
You also need to be able to manage uneven terrain, lots of escalators, stairs and paths where handrails are not always available, and get on and off the bus several times a day. You need to be able to keep up with the group while walking through very crowded train stations, sometimes while carrying your own carry on luggage and be able to get on and off the trains in just a few minutes per stop. This is definitely not a leisurely paced tour. You will be on the move all day, every day, for two weeks. You will see and do a lot on this tour, and it will be well worth the effort.