At St. Mihailov Academy, a string of murders targeting young women has stirred fear. Amidst this chaos, Mafuyu Oribe and Tomo Yamanobe, adopted sisters, come across a wounded young man after a rough day at school. When Mafuyu becomes a target of a notorious serial killer, the killer surprisingly seeks an artifact linked to Tomo's father. Fortunately, the enigmatic Sasha, the man the sisters nursed back to health, intervenes just in time, using his unique powers as a Qwaser to save Mafuyu. Sasha, who can wield elements through Soma obtained from women's breasts, defeats the murderer with his iron-manipulating abilities. As Sasha joins the academy, a compelling and action-packed journey unfolds, promising a school year filled with intrigue and danger in Seikon no Qwaser.