Nana Osaki (voiced by Park Romi), a punk girl with a dream of music, once formed a band BlackStones with her boyfriend Ren Honjo (voiced by Kiuchi Hidenobu), her good friend Tai Takagi (voiced by Kawahara Yoshihisa), and Nobuo Terajima (voiced by Seki Tomokazu) in her hometown. Later, Ren was poached by the popular band Trapnest to develop in Tokyo, and the two were forced to break up. Two years later, Nana also decided to go to Tokyo and find Tai and Nobuo to reorganize BlackStones, vowing to compete with Ren's Trapnest. Nana Komatsu (voiced by KAORI), an unreliable small town girl who is always immersed in the dream of love, suffered from long-distance relationship because her boyfriend Shoji Endo (voiced by Hiroki Takahashi) went to Tokyo to study, and now she finally has the opportunity to move to Tokyo to accompany Shoji. The two girls whose names are pronounced the same "nana" met on the Shinkansen to Tokyo, and by coincidence, they both liked the same "707" apartment, so they decided to rent it together. Two girls with very different personalities, plus two boys from competing bands, from then on, life, dreams, love, and setbacks are intertwined and can no longer be separated...