A Summer Day, Your Voice: Tetsuo Togami is in the 2nd grade of high school. Due to a fight, he is hospitalized. There, he meets Maiko Takashiro. She has an incurable disease. She also has a hearing disability and is unable to talk. At first, Tetsuo becomes embarrassed but begins exchanging text messages with Maiko. Through the text messages, he begins having feelings for her. Even after his discharge from the hospital, he goes to visit Maiko every day. They promise to go out together on Maiko's birthday, but her condition worsens.