Kubo Emiko, a drama club student at the prestigious Gyosei High School, is drawn to the confident and spirited Mizuho Kaoru, a returnee from Paris who joins the equestrian club with her beloved horse Electra. Despite being born only a year apart under the same Aries zodiac sign, the two share an uncanny kinship. Emiko falls for the honor student and student council president Takashi Isozaki, while Kaoru becomes involved with the delinquent Tsukasa Yuki. As their relationships develop, a devastating family secret surfaces: Emiko and Kaoru are half-sisters, connected by the same father. Their lives are further entangled by the cruel circumstances that force Takashi and Tsukasa to leave school. In unwavering devotion, Emiko and Kaoru each choose to quit school to stand by the boys through hardship. The story follows their intertwined journeys of love, sacrifice, and resilience as they navigate jealousy, parental opposition, and personal tragedy, ultimately striving to be united with the ones they love.