東京國際動畫博覽會
At the Tokyo International Anime Fair 2007 in March, Geneon announced that they have acquired the license to the anime and Scholastic announced they have US distribution rights to the novels. After Geneon discontinued its distribution division, the rights transferred to Media Blasters. The series premiered in the United States at 1:30 a.m. on August 24, 2008 on Cartoon Network's Adult Swim block, but was dropped from the schedule without warning or explanation on January 15, 2009 after two runs of the first ten episodes.