The story tells about a boy named Kazuya who lost his sister in a battle with aliens that attacked humans. He inherited his sister's will and entered Geneticus, a school for fighting aliens. It is actually a school where boys and girls fight each other to hone their skills in order to fight against unknown enemies at any time. Kazuya senses a figure similar to his sister in Satyrissa, the strongest female student in the school and known as the Queen of No Contact, and begins to approach her.