In 2036, Ryosuke Fujii (31) makes triumphant return to his hometown as a world famous photographer. An exhibition of his work is on display there and he meets up again with an old childhood friend, Kento. Kento shows Ryosuke a dinosaur he has made based on the legendary “Biwassie” the “Nessie” of Lake Biwa. One summer over 20 years ago, 11-year-old Ryosuke, Kento and his cousin Saki, spotted a mysterious, big, black object, apparently swimming on the surface of Lake Biwa. Naturally, few believed them, but Ryosuke learns that his late mother, Yumiko, a famous photographer, also saw the same creature and she had done a lot of research into the legendary Dragon God, Biwassie.