Here is what the website has to say:
"The Save Japan! website was established immediately after the Great East Japan Earthquake to support the affected parts of the country by providing information on area-specific relief efforts. UNIQLO is working with the Condé Nast Group—a supporter of the Save Japan! website and the publisher of Vogue Japan and GQ Japan—to create T-shirts featuring messages of encouragement from artists around the world. UNIQLO plans to donate approximately 100 million yen through the sale of Save Japan! T-shirts to the Japanese Red Cross Society, to back recovery efforts in northeastern Japan. "
And here is a look at the designs...so snap up one fast and help the campaign: