 The cities name is never mentioned in the book, but in early drafts when Hiro was the main character, he refers to the city as Yokohama.The city is not shown to have any rusty ruins near it, so it is presumed to be built over the remains of the modern-day city of Yokohama, since Aya describes her apartment in Shuffle Mansion as having a view of mountains and of a coast; modern day eastern Yokohama has a view of both.Also, the large mountain that Aya and the Sly Girls visit multiple times in the story is presumed to be Mt.