My 13 (2008)

Jonathan is in love with Julie, the most beautiful girl of his school... However, Julie doesn't even know him. He becomes friend with Charles, Julie's brother. One day, he sneaks in Julie's room to steal her diary. Back home, he finds in the diary a drawn heart, with the quote "I love Jonathan"... Back to his new friend Charles' home, he realizes that the diary belongs to Charles, himself...