Sell your clients on experiencing something beyond Tokyo as well to really maximize the trip.
One rising destination to explore that is a great example of an off-the-beaten-path destination for a post- or pre-Olympic vacation is Shikoku, the smallest of Japan's major islands. It's best known for the Shikoku Pilgrimage, a long walking path that involves visiting 88 temples in about six weeks. While your clients might not want to do this long walk, they can visit these stunning temples around the island, such as Chikurinji Temple near Kochi.
In addition to temples, Shikoku is home to historic wonders like Himeji Castle in Himeji and Kochi Castle in Kochi, as well as the architecturally-appealing white-colored UDATSU town in Mima. Those who enjoy outdoor adventure will fall in love with the Iya Valley, home to a thrilling vine bridge, waterfalls, Ryugado Cave, an Oboke Pleasure Cruise, and a five-star stay in a
traditional ryokan hotel with a lovely onsen called Hotel Iyaonsen.