Sachiko Ogasawara, a gifted and polished pupil at Lillian Girls' Academy, conceals a troubled nature beneath her image as the school idol. She harbors a strong dislike for men and is appalled by the prospect of dancing with a male classmate in the forthcoming school production. Wanting to relinquish her part, she offers to the Yamayuri Council—Lillian's student body—that she will instead demonstrate her value by locating a petite sœur, an underclassman who would become the protégée of her grande sœur.
To everyone's surprise, Yumi Fukuzawa, the first‑year whom Sachiko selects as her petite sœur, declines the offer. Senior council member Sei Satou then issues a challenge: if Sachiko can persuade Yumi to accept the role, she may withdraw from the play. Though Sachiko frequently finds it hard to bond with others, she resolves to try everything possible to win Yumi's favor.
Studio DEEN Japan