Danish director Malou Reymann makes her debut feature with this gentle, open-hearted drama based on her own childhood experience of her dad transitioning to female. The story is told from the perspective of 11-year-old Emma (Kaya Toft Loholt). But Reymann turns the dial on the empathy machine up to 11 – balancing the feelings of all her characters so evenly and with such generosity that in the end I did feel that the niceness of her film left it a bit pale dramatically.

It’s set in the 90s of Reymann’s childhood, which explains the air of bafflement when Helle and Thomas announce to their two daughters that they are getting a divorce because Thomas (played by male cis actor Mikkel Boe Følsgaard) is transgender. Football-mad Emma reacts angrily: “You can’t just decide that for yourself,” she says, heartbreakingly. She refuses to see her dad for months until a hilariously awful family therapy session; Emma sits with a scarf wrapped around her head so that she doesn’t have to see her dad as a woman, now called Agnete. In these scenes, Reymann is hyper-alert to Emma’s pain but also beautifully observes Agnete’s radiance at finally being able to live as her true self.

Time passes. Agnete travels to Thailand for surgery. What’s so sensitively shown here is how family dynamics must be remapped. Emma, who hates pink and never wears skirts, previously identified with her dad. But now it feels to her that Agnete, in her floaty chiffon dresses, has more in common with her Britney Spears-obsessed big sister Caro (Rigmor Ranthe). The directness and honesty of the storytelling is really affecting in places; and Loholt is so natural and touching as Emma. There’s a scene in which she sings a song at her sister’s confirmation that brought me to tears with its sheer loveliness.

• In cinemas and on digital platforms from 2 October.