Hawaii, Oslo is the story of a handful of people who cross one anothers paths without necessarily knowing one another, during the hottest day of the year in Oslo. Frode and Milla are having their first child, whom they are told will not live long. Bobbie-Pop, a faded singer, tries to commit suicide. Leon, an institutionalized kleptomaniac, is waiting for the arrival of Åsa, with whom he has a 10-year deal to get married. Leons brother Trygve fetches Leon from the institution to celebrate his birthday, but Tryge actually plans to use this leave from prison to run away. And the angel Vidar, Leons best buddy at the institution, sees things no one else can see and just might be able to save everyone.