Tiina decides to reconnect with his aged and bohemian father living alone. With her reluctant daughter and new husband, they move in and start to renovate the old house. However, neither the renovation nor facing the past is effortless.

The film follows Sanna, who sets out to document the countless ways there are to ruin a marriage for her doctoral thesis.

Headfirst is a black comedy about a single mother with anger management problems and her teenage daughter who is always in trouble at school. With yet another school comes a new teacher and a blast from the past for the mother. Before long, an accidental pickpocket and a notoriously lousy storyteller teams up with this one dysfunctional sort of a family. Nothing is the same anymore. Headfirst is a story about missing teeth, strange friends, hidden dreams and long-gone love. And about a hare.