My parents are getting off of a cruise on Saturday, July 26th and are interested in staying a day in Yokohama to see the sights before heading up to Tokyo, where they have been many times. At first I didn't believe my parents when they were telling me that prices were very high or that rooms weren't available but when searching some basic hotels (Monterrey, Washington, etc.), there are indeed no rooms available.

What's going on that weekend in Yokohama? Is it just the cruise itself that's causing the lack of room availability? The only holiday near that date is Marine Day and Obon is still weeks away from late July.