The Opening Partita. Kanade Kohinata, who was once called a genius violin girl, receives an anonymous letter at a concert she appeared in one day. Around the same time, she leaves her hometown to attend Seisou Gakuin in Yokohama, and is invited to a concert featuring her childhood friend Kisaragi Ritsu, and heads to Yokohama with Ritsu's younger brother Kyoya. It's been a long time since I met Ritsu, and the atmosphere has changed a little from the old days. At the concert, the opening of the "National Student Music Contest" was declared, and the venue was filled with excitement. And Kanade and the others are told by Ritsu to "come to me"...