At the renowned all-girls academy, Midgar, Yuu Mononobe breaks tradition as its sole male student. This distinguished school houses the enigmatic 'D's, girls with unparalleled abilities to wield dark matter into formidable weaponry. The emergence of these gifted girls coincided with the sudden appearance and subsequent disappearance of destructive beings called 'Dragons.' Born with symbols and powers akin to these vanquished foes, the D's, including Yuu, converge at Midgar to hone their skills against future Dragon threats. As the only male D, Yuu navigates complex relationships within the student body, reuniting with his estranged sister also enrolled at the academy, to confront and eradicate the looming menace posed by the formidable Dragons.