VENICE — Two Japanese teenagers, Shota Sometani and Fumi Nikaido, won the Marcello Mastroianni Award for best young actor and actress at the 68th Venice International Film Festival on Saturday for their performance in the Japanese film "Himizu" directed by Sion Sono.Sometani, 19, and Nikaido, 16, became the first Japanese actor and actress to take home the prize, which was created in 1998.At press conference in Tokyo on Sunday, the actors expressed their joy at receiving the award."It just seems so unreal," Sometani said. "I think the award was given to teenagers including myself who will create a new future" for Japan.The film portrays a teenage boy, abused by his parents, and his female classmate against the backdrop of the earthquake and tsunami disaster in March."I guess the award was given for our devotion to our work in playing the roles amid the anxiety of not knowing what will become of Japan in the future," said Nikaido.Sono, 49, changed the background of his movie's story, originally based on a Japanese comic, after the March catastrophe ravaged northeastern Japan, depicting the teenage boy's struggle to overcome his suffering with the help of his girlfriend. The film's locations included an area in the city of Ishinomaki, Miyagi Prefecture affected by the disaster.In the festival's Orizzonti selection of films reflecting new tendencies in international movies, the Japanese film "Kotoko" directed by Shinya Tsukamoto won the prize for a full-length film.In 2002, Tsukamoto, 51, won the jury's special award in the festival's Upstream category.The Golden Lion top award went to "Faust" directed by a Russian director Aleksander Sokurov.