Olsenbanden jr. is about Olsenbanden's first coup. The story takes place in the 1950s and the gang members are only 12-13 years old. Egon Olsen meets Benny Fransen and Kjell Jensen when he, as a new student at the school, makes his first friends. And it does not take long before they end up in trouble. Egon lives in an orphanage, and each year the orphanage is awarded a large sum of money to celebrate Christmas for. This year, however, the Christmas fund is empty, and Egon suspects that the law firm that looks after the fund has emptied it of money. The Olsen band, led by Egon, starts the hunt for the Christmas fund, and the gang gets into many exciting and fun situations - as the Olsen band is also known for.