From first page Berkley paperback September 1997:

21st century Tokyo, after the millennial quake. Is something different here, in the very nature of reality? Or is it that something violently new is about to happen...

Colin Laney is here looking for work. He is an intuitive fisher for patterns of information, the "signature" an individual creates simply by going about the business of living. But Laney knows how to sift for the dangerous bits. Which makes him useful -- to certain people.

Chia McKenzie is here on a rescue mission. She's fourteen. Her idol is the singer Rez, of the band Lo/Rez. When the Seattle chapter of the Lo/Rez fan club decided that he might be in trouble in Tokyo, they sent Chia to check it out.

Rei Toei is the idoru -- the beautiful, entirely virtual media star adored by all Japan. Rez had declared that he will marry her. This is the rumor that has brought Chia to Tokyo. True or not, the idoru and the powerful interests surrounding her are enough to put all their lives in danger.