The box that the Slusho! hat and t-shirt came in was very plain, but inside were some pieces of Japanese newspaper. I doubt they contain any clues, but it's a nice little touch. Nevertheless, I have scanned them in so they can be analyzed. I found the horse racing picture interesting, since I work in the horse industry.
If anyone reads Japanese, or has different pages from the paper, send me an email, and we can piece them together while we wait for more clues.
I did notice that page 21 has a website on it - www.jal.co.jp/happiness/ (Japan Airlines)
UPDATE: I have added 8 more pages. 3 from 1-18-08.livejournal.com, and 5 from ???. I now have pages 9 through 24.