WHEN I WAS A CHILD, reading adventure stories in a house by the sea, I often dreamed about worlds above the clouds. One day, my father took me on a hike up a nearby mountain. It was just a little one–a rocky summit poking through a thick carpet of trees–in the Fukushima prefecture of Japan. But for the first time, I thought I could touch the clouds. It was as though I’d walked into one of the illustrations in my books.