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From The Lost Media Wiki
Accoding to this blog post (link 1), the characters are "partly based on the people involved". Furthermore according to Martin Lawrence (link 2), the Roppongi hills centre's real estate mogul; Minotu Mori contacted Takashi Murakami to replace a major Japanese ad agency just four months before Roppongi hills was set to open. Since Roppongi hills opened on April 25th 2003, this means production started in December 2002. 1. http://2016.tiff-jp.net/en/lineup/works.php? 2. id=250https://www.facebook.com/martinlawrencegalleries/photos/the-planet-66-characters-were-invented-by-murakami-to-advertise-real-estate-mogu/2237625209605269/