Some details of the event:
Date: December 19th - 25th
Venue: Hanshin Department Store Shop 8F, Umeda, Osaka.
There will be exhibition of Gunpla work and history, as well as fun attractions for kids and adults.
Image and information is from Hanshin Department Store Shop.
For your information, another Gundam Expo will be happening during Gundam Expo Osaka. This one in Hong Kong, and it will be on from December 17th till January 3rd 2010.
Also, Gundam Expo went to Hiroshima for the first time earlier this year as well. Slowly but surely, it's going to cover every major city in Japan. ^^