Complex sentence: On April 27 Anime Expo, the largest anime convention in the United States, announced that AKB48 would be a guest of honor and the group performed on July 1 at the Nokia Theatre.
Split into simpler sentences: On April 27, Anime Expo, the largest anime convention in the United States, announced AKB48 as an official guest of honor. The group performed there on July 1 at the Nokia Theatre.