Tokyo 2020 Prep: Touring Outside Tokyo

The Olympics are the main goal of my trip to Tokyo in less than six months. (!!!!) Last weekend, I spent some time filling my calendar with all the stuff I've already accomplished for the trip, including airline reservations, hotel reservations, and sporting events. After I filled it out, I realized I have a few holes! I have two nights near the beginning of my trip that I still need to find a place to stay...plus the entire third week. (Surprisingly, I don't have holes in my Olympic events. Tell my 2018 self that fact and she'd be shocked!) When I booked my airline reservations, I spent a lot of time trying out a bunch of combinations of times to travel as well as places from which to commute. In the end, I went with a three week itinerary because it was the cheapest way to maximize my time but still be in Japan for the entire two weeks of the Olympics. That means that after my final event (which is on Day 16), I need to find something to do! I'm guessing tha