As the impending closure of Nanagou High School looms, Hirofumi Mizusawa, a second-year student, stumbles upon a mysterious 'flying orange light' while toiling over his summer assignments one night. Intrigued, he shares this discovery with his friends Akira and Ryo, sparking a joint quest to unravel the enigmatic origins of the light, leading them down an unforeseen path of adventure and suspense.