Messing with fireworks, ring and run and a lot of football practice. This makes Ky really happy, but she has also been unhappy for years because she has a girl's body. Last summer Ky finally managed to tell her parents she wants to become a boy, and would like to have a different name: Niels. Together with her friend Sterre, who used to be called Tibor and therefore has a boy's body, they tell their new secondary school class that they are transgender children. It is the beginning of a new life as Niels. 'How Ky turned into Niels': the search to find out who you are and the right to be yourself, about boys and girls stuff, hormones and more of those confusing things.