When Suzu (Kaho Nakamura) leaves for school one morning, she’s just an ordinary teenager: a little shy, a little awkward, and nursing a blush-inducing classroom crush. But by the time she gets home that evening, she has unwittingly become a global sensation. In real life, she still lives with her father and pet dog in a rural town on the island of Shikoku. But inside the virtual realm of U, she is Belle – a willowy pop star with a shock of pink hair and peachy freckles that run across her cheekbones in a stripe like war paint.

Suzu has been a keen musician and vocalist since childhood, but following the death of her mother some years ago, she hasn’t been able to bring herself to sing a note in public. But now, with nothing more than a karaoke mic and a smartphone hidden underneath her duvet, she can reach an audience of billions – and her debut performance, posted the previous evening, has just gone viral.

Such is the dual existence led by the young heroine of the extraordinary new film from Japan’s Mamoru Hosoda. Belle is a beautifully observed, dazzlingly animated sci-fi fairy tale about our online-offline double lives – it’s Hosoda’s finest film since 2012’s Wolf Children, and perhaps his best to date. The plot is a loose reworking of Beauty and the Beast – Hosoda even pays spectacular homage to the whirling ballroom dance in Disney’s 1991 adaptation – but he ingeniously turns the fable inside out, using it as a means to examine the ways in which our virtual existences can simultaneously liberate and trap us.

Since his early work on the Digimon franchise, Hosoda has been enthralled by abstract digital spaces, and U is his most striking to date: a Fifth Element-like criss-cross metropolis, teeming with weird cartoon avatars that are auto-generated from the biometric data of their users. (It must be the first social network where who you are on the inside is what counts.)