Steph and Agnes go to the same school but don't like each other at all. Agnes with probably the best grades in the whole city, and Steph a little more of a bad girl. When their parents start dating during the summer they leave the two girls and Agnes' sister, while going on a trip through Europe. They have to live together in Agnes' apartment together...

A free-spirited young guy moves in with his type-A, tightly wound sister under the guise of being his niece's nanny.

Masha explains why there's no need to be scared of things like monsters, the dark, going to a new school, thunder and other common childhood fears.