My Sister Momoko

Momoko, a mentally and physically disabled girl, attends a special school. Each morning, she becomes upset because she cannot go to a regular school like her twin brother, Riki. Her family calms her by singing her favorite song, "The Song of Frogs." One day, Momoko cheers Riki on during a dodgeball game at an open classroom day, and Riki's team wins. Ryuji, whose team lost, becomes angry and insults Momoko, causing Riki to react violently. The following year, an integrated education experiment begins, and Momoko starts attending Riki's school. Unfortunately, her physical condition worsens, and she is hospitalized. Riki and his classmates decide to win a relay race to cheer her up. However, Ryuichi, the fastest sprinter, refuses to participate.