Two years ago, Mitsuki Kouyama's friend, Eichi Sakurai, moved to America before she could confess her feelings to him. Though she cannot contact him, they made a promise to fulfill their respective dreams: Mitsuki wants to become a professional singer, and Eichi an astronomer. She hopes that one day her music will reach him across the world with a brilliance like that of the full moon. There is just one catch: Mitsuk...