The year is 20XX, an era when the "metaverse" has become a part of everyday life. One day, Ichidou Ikki, an elementary school student at Shinkai Academy, encounters a mysterious enemy called the Unknown. He is saved by his senior from the middle school, Taisei Taisei, the driver of the Shinkalion E5 Hayabusa train. However, Taisei is seriously injured in an attack by the Unknown...!