This is the most widely known and one of the simplest walks, due to its simplicity its virtually impossible to get lost. If your partner is not use to walking, this is the best route for initiation.
The course start on Tokyo station on marunouchi central gate, walk toward the plaza in front of the palace, continue to the left until reaching the sakuramon gate, continue around the palace until chitorigafuchi, continue north kitanomaru park, continue south passing takebashi, and otemon until reaching back to the plaza in front of the palace, the course finish back in Tokyo station, a brisk 7.2 Km walk.