In the serene haven of Sentan Island, shielded from the warfare raging between the Northern Government and the Southern Continent Free Zone, Akiyuki Takehara resides with his mother, Fusa, while his father, the esteemed town doctor Ryuzo, remains distanced. A routine day takes a drastic turn when Akiyuki and his companions, Haru and Furuichi, become ensnared in a sudden explosion at school. Amidst the chaos, a mystical light engulfs Akiyuki's arm, plunging him into agonizing torment. Before he can grasp this enigmatic occurrence, a silver-haired girl from his bus ride unveils a power that shatters all he once knew.