At Andrude Ocean School, set within a sprawling ocean metropolis, a dedicated teacher reflects on the rescue he performed three years earlier. A quiet student continues to harbor unspoken feelings from that moment, and her twin—an android built by their late parents—quietly works to bring those emotions into the open. As the synthetic sister navigates the memories she carries, her own sentiments begin to shift between the two people she holds closest. This premiere episode introduces the delicate bonds forming amid the waves of the city.