On the 13th anniversary of the detonation of the O-E bomb, Ibuki spends the day with her mother and step-father, but she argues with him when he insists that she quit her involvement with Dai-Guard. She gets called back to headquarters because of a Heterodyne alert, and encounters Domeki who is intrigued by Ibuki's father, Eijirou Sakurada’s research. A Grub-Type Heterodyne appears similar to the first one of 13 years ago...