The three sisters, Mafuyu, Kanade, and Ichika, are daughters of a High-Class Noble. Despite having different mothers, they share a close bond and protectiveness toward each other. Their father trains them with swords to become knights, but society views female knights as incompetent. because of this, they are forced to disguise themself as boys to meet this criticism and judgment. The three girls named Mafuyu the oldest, Kanade the second oldest, and Ichika the youngest.