While the GTO is preparing for its 25th anniversary event, elsewhere, the G-society is having a ceremony of its own. Led by the mysterious Gacktoel and his Shadow Workers - Torch, Shade, Rubis, Saphir, Letuchie, and Pauk - the G-society is made up of Nouvlesse who were thrown out of power thanks to the GOTT. On this day, they declare independence and set their sights on the GTO, particularly on Chief Hiver and the three elite ES member teams.
GTOが創立25周年記念行事の準備に追われる、ちょうどその頃。Gソサエティの移動要塞エルデ・メテオールでは、総帥ガクトエルによる建国宣言が行われようとしていた。GTOを「敵」とする彼らの目的とは――!?
GTO는 창립25주년 기념행사 준비로 바쁜나날을 보내고있다. 한편 GTO의 반대파인 G소사이어티는 총수 각트엘을 중심으로 하나의 자치국가임을 선포하고 GTO와의 싸움을 공포하게 되는데…