It is the first school day at the junior high school for Bert Ljung and his friends, Åke and Lill-Erik. At school, Yoghurt-Leila is the big star. She is in ninth grade, is an advertising model, cool and just about everyone admires her. As soon as Bert sees Leila, he falls flat on his face. But how is he going to make her notice him who is only in seventh grade?! Soon a lively story begins through an embarrassing theme day, raw food buns, an unforeseen toilet visit and not least - two secret diaries.