A tragic, pathetic fate for a young girl strangled by social convention and propriety; an explosion of youthful sexual experimentation and hormonal energy; radical statements about traditional social structures wrapped up in slapstick farce. Those are the key elements of Frank Wedekind’s Spring Awakening, which has just opened at the Union Theatre.

So radical is this script that it is hard to believe it was written in 1891; far less surprising that it was not performed unexpurgated in the UK until 1974. The challenges for the Union Theatre are today, however, not from moral guardians but from a play demanding a huge cast (17 actors in total), many playing young adolescents, and embracing this huge range of moods and registers.

It is a challenge that director Aoife Smyth and producer Sasha Regan, and their actors, have risen magnificently, aided by a lyrical translation by Edward Bond. (So often it seems impossible to render German into “natural” English, but he’s managed it here.)

If there’s one single lesson from the play it is that Philip Larkin wasn’t saying anything new about parents and children with his “they fuck you up” line … “Parents are bringing children into the world so they’ll have something to shout at,” complains one young character.

The central figure, Wendla, is a 14-year-old desperate to hang on to her childhood and resist the restrictions of womanhood. The boy who will be her downfall, Melchior, is about the same age. To be believable as these ages is no small challenge for an adult actor, yet Kerry Fuentes and Ryan Gage here rise to the challenge, with bursting youthful energy that never comes across as false.

What’s sad, and gripping, is that how much of the societal critiques that here fly out of the mouths of babes are still all too relevant, in the age of the silver ring thing. The central tragedy of the play arises from the inability of Wendla’s mother, Frau Bergmann, to even imagine about speaking to her daughter about the birds and the bees. Sensibly, she’s played by Caroline Devlin not as some prim matron, but a woman consumed by her own shame and confusion. “Tell that to a 14-year-old girl; no I’d sooner the sun go out,” she says of the facts of life, and of course hers does.

The boys are trapped in a mindless, suffocating traditional grammar-school regime of endless homework and repressive rules, enforced by as crusty and crass a collection of masters as ever graced a third-class English public school. Melchior, in a sane and just system, would be the star pupil but here, although his talent is recognised, it is feared, suppressed, for he shows signs of possessing an original mind.

Part of that independence comes out in his friendship with Moritz (Jeremy Joyce), the poor boy struggling beneath the waves of academic drudgery being flung at him. Indeed Moritz tells his friend — too bright to really grasp his difficulties — that he knows he’s been set up to fail, and then what will his father say? His fate, like Wendla’s has a grim inevitability, yet also there’s a spark of blind, malevolent fate as the free-spirit Thea (Orna Salinger), fey, free, yet terribly vulnerable and exploited, almost, but not quite, saves him.

There’s only one real area where this production falls down, in its all too literal interpretation of the headless Queen, a mythological figure who roams the set at irregular intervals. The final scene in the graveyard does too, perhaps date this play a little – a neat metaphysical ending to a highly human drama is a reminder that this was, after all, Wedekind’s first play, and the 19th century. But in all other respects this is a play that fits all too comfortably in the heart of the controversies of the early 21st – our inability to deal with sex in a sane, grown-up way, as the children just might, were they to be given the chance.

The Union Theatre, a biography of Frank Wedekind.