by William Gibson
Idoru is an incredibly famous cyberpunk novel by William Gibson. If you call yourself a geek, it's pretty much required reading. Well, every William Gibson book is actually required reading for nerds.
Anyway, the story in the book revolves around the fact that one of the world's most famous rock stars, Rez, announces that he plans to marry a virtual idol. Basically it's like if Jack White announced he was going to marry Hatsune Miku. One of Rez's fans from the US travels to Japan to figure out what is going on. A quantitative analyst named Laney also goes to Japan for a mysterious job opportunity. Both get embroiled in the inevitable conflict in both meatspace and cyberspace.