AnotherSky permite que os jogadores vejam a narrativa de uma das três principais escolas rivais introduzidas no terceiro título.

The protagonist has finished playing at a concert with a lackluster performance. Her grandfather notices her artistic slump and consoles her to reconsider her love for music. He advises the protagonist to live with her mother for a change of pace. As she broods in Sendai's streets, the protagonist spontaneously overhears Arata's trombone and joins him for a live duo. He leaves after their performance, casually stating his club name and high school before disappearing. Feeling invigorated by the experience, the protagonist decides to enroll at Shiseikan High School.