The transition from Spring to Summer is interesting for me in that it is marked by nearly the same thing as they were back in Arizona. When we traveled up to Sedona to camp for the summer there were always cicada humming away. In Japan, too, semi (蝉) or cicada mark the end of the rainy season and the start of summer.
The large black bugs show up in trees and gardens, and their shells can be found on nearly every tree. The bugs become a favorite toy of children as they run with long poled nets in the hopes of capturing their own noise maker. They seek out the shells too as interesting toys and odd curiosities. The bugs are so pervasive they have become almost a symbol of summer in Japan, with the call of the cicada luring children outside to play.
If you would like to hear what the cicada sound like at one of my schools. Listen to this: Semi (Cicada) Audio