When delegates from the dying planet Barm arrive on Earth seeking sanctuary, a political assassination shatters any chance of peace. The Barmian leader falls murdered, and Earth's negotiators take the blame. In the chaos, scientist Isamu Ryuuzaki is killed, leaving behind a son who would grow into humanity's last line of defense. Years pass. The Barmians, now calling themselves Valerians, wage war against Earth under the command of Admiral Richter, heir to the murdered leader. He sends wave after wave of mechanical soldiers to devastate the planet. Standing against this invasion is Kazuya Ryuuzaki, Isamu's son, who pilots the mighty mecha Daimos alongside Erika, a Barmian defector searching for the truth behind her people's betrayal. Caught between two worlds, Kazuya and Erika must navigate impossible choices: love blooming amid warfare, trust breaking under suspicion, and the haunting question of whether redemption exists when everything built on deception crumbles. War and romance collide as they fight not just for survival, but for a future where enemies might become something more.