 Johanna Tähtinen s husband Ykä burns down their house and goes to jail so Johanna and daughter Liisa are left with nothing. Johanna, not being very intelligent, doesn t know what to do, so it s up to Liisa to find them a place to live. In the meantime mother-less teens Matti and Missu get tired of taking care of the house and their scientist father, widowed Hannu Hurmala, and put an ad in the newspaper to find a housekeeper. Liisa spots the ad which promises also an apartment. Matti and Missu, desperate, hire Johanna without asking their father. Hannu, dating super-jealous school teacher Margit Haukkamaa, isn t happy about the new housekeeper and her daughter...