A mute middle school boy named Tatsuki finds his only emotional support in an anonymous online singer known as Rabi. This secret favorite artist, still relatively unknown, is a private source of comfort for him. After Tatsuki begins attending a free school in the area where his grandfather lives, he discovers that a staff member named Yosuke is also a devoted Rabi fan. While Tatsuki should be happy to find a fellow supporter, he instead finds himself irritated because Yosuke seems completely different from him as a person. The story follows their complicated friendship as it develops around their shared admiration for the singer Rabi. Tatsuki eventually resolves his initial hostility and accepts Yosuke as a fellow fan, but remains unaware that Yosuke is actually the person behind the Rabi persona. Yosuke struggles with whether to reveal his true identity, especially because he knows that the ideal image Tatsuki has of Rabi is very different from who Yosuke really is. In a later development, Yosuke learns the reason why Tatsuki lost his ability to speak and becomes determined to write a new song specifically for him. This proves difficult for Yosuke, who has only ever written songs for himself before now. The story is set in a rural region featuring mountain paths where Tatsuki initially gets lost, and the free school serves as a central location where the characters interact. The narrative explores how the simple phrase daijōbu can form the basis of a meaningful connection between two people who appear to be opposites. The author is Naoko Kusaka.