View source for Detective Conan Quarter of Silence

The 2011 Japanese animated mystery thriller film is the fifteenth film installment of the manga and anime series Case Closed. The film was released on April 16, 2011. This film celebrates the fifteen anniversary of the anime. Magic File 2011, ties in with the film and was released the same day as the film's premiere.Summarize the following text using ONLY facts from it. Do NOT invent references, emails, or links. If the text doesn't mention something, leave it out. The plot involves the construction of a dam in Kitanosawa, a fictional town in the Niigata Prefecture. Due to the dam's construction, the citizens of the town were forced into a new town and their old homes were drowned by the dam. The next day, Tachihara's son, Touma, awakens from his eight-year coma with no memory of his accident. The group reveals they were all childhood friends and were part of the group which relocated to the new village. They reveal it is their first gathering in eight years since Yamao was in prison for killing Toono's sister, Natsuki Toono, in a hit and run.