On the surface, Oshima Shino (Minami Sara) is a very cute ordinary girl, but once she opens her mouth, her severe stuttering will expose her flaws. Because of her stuttering, Shino has been bullied by her classmates since she was a child, living in ridicule and discrimination for many years, and even her teachers sometimes hurt her fragile heart unintentionally. By chance, Shino met a girl named Kayo (Maita Ayame), who is a child who loves singing very much. Although she is tone-deaf, this can not extinguish her passion for music. After listening to Shino's singing, Kayo invited Shino to form a group with her to participate in the competition held by the school. Although Shino speaks intermittently, her singing is extremely beautiful. Using her singing, Shino began to gradually change the prejudices of her classmates around her.