With Professor Yuuko Kouzuki"s inventions and Kasumi Yashiro"s psychic gifts, cadet Takeru Shirogane is sent back to his native world. Time is short, so he seeks Yuuko"s assistance there to finish the Alternative IV initiative—the sole defense humanity has against the BETA, an alien force attacking Earth. As the anti‑BETA effort draws to a close, Takeru and his fellow trainees graduate from Yokohama"s pilot academy. Their mission is to synchronize the project across dimensions.
Yet during a trial of the new Tactical Surface Fighter operating system—massive suits humanity uses against its foe—the BETA launch a surprise attack on Takeru and his squad. He escapes barely alive, but the brutal death of a close comrade leaves him deeply scarred. The loss haunts him, eroding his confidence.
Unable to muster courage, Takeru retreats to the alternate realm, where he suffers a comparable loss. Yuuko"s hypothesis states that individuals from parallel worlds inevitably face the same tragedy. Consequently, Takeru must confront his trauma if he wishes to shield those he loves.
