The elite Prism Star training academy Schwarz Rose, under its director Jin Norizuki, declares open war against Edel Rose in the upcoming Prism Show trio tournament known as PRISM.3. The competition brings together teams of three performers to deliver Prism Shows, the fusion of song, dance, and figure skating that defines the world of Prism Stars. Representing Edel Rose in the tournament are three members of the unit SePTENTRION: Yukinojo Tachibana, Kakeru Juuouin, and Minato Takahashi. Each of them carries personal feelings and hidden hopes as they prepare to step onto the stage. Other powerhouse units quickly enter the fray. Over the Rainbow, the legendary trio of Koji Mihama, Hiro Hayami, and Kazuki Nishina, announces its participation, as does the newly formed TRI-UMviratuS. Adding another layer of tension, Minato is directly challenged by his own younger brother, who now goes by the name Takaya Gettaway Prince and stakes his sister Tsubasa as the prize of their duel. As the tournament approaches, the bonds between Yukinojo, Kakeru, and Minato are tested not only by the strength of their opponents but by unsettling signs of anomalies within the Prism World itself.