No neat folding of T-shirts here. Toco Nikaido and her fearless, 33-strong troupe are going to turn the theatre into a playground and give us all a ‘happy, hysterical time’. So for 45 intense and colour-saturated minutes they bombard the audience with sound, light, dance and liberally flung stuff. It’s messy, loud, thrilling and exhausting to witness. We get very wet.

Nikaido wants to make performance that resonates with young people and shares their ‘genki-ness’ (which roughly translates as energy and liveliness). Part political rally, part rave, Extreme Voices uses J-pop tunes, a chorus-line and projections of manga-style graphics and slogans (my favourite being ‘nommal [sic] theatre is boring’) to create a high-octane pastiche of Japanese youth culture. The music is fast, beat-heavy and lip-synched: it’s weird when performers are sitting on your lap and miming lyrics; they are so physically present throughout it seems odd not to hear them too. But it frees them to focus on the complex business of performing this show, which they do with an amazing level of skill.

Choreography is whip-tight: lots of symmetrical tableaux and ensemble movement, blending Japanese and Western dance-styles, as cheerleader pom-poms and knee-socks give way to bondage undies. As for props, the theatre is riddled with plastic buckets holding confetti, balls, flowers, seaweed and water – gallons of water, which is flung with glee at the rain-poncho’d audience. The on-stage picture is similarly dense. Songs are performed behind life-size Russian dolls, there are light-sticks galore including some shaped as leeks, there’s a song about technology – ‘who controls the future, who controls the past?’ – during which big cut-outs of monsters romp about. The energy is infectious and the anarchy controlled. Through very cleverly directed movement flow everyone gets to the right place in time for the next costume change, the next lighting effect, or the next audience invasion.

Whilst it’s the power of the pack that impresses most, it is Amanda Waddell, a Texan long-resident in Tokyo, who leads the singing and what there is of narration, in English. She brings a touch of the rodeo to the mix and is a powerful presence, skewing the ‘otherness’ a wholly Japanese cast would offer, perhaps as a symbol of America’s growing influence on their aspirations.

Extreme Voices is an extreme spectacle, beautiful to watch and hugely photogenic. It hurtles along blazing with noise, colour, energy and perpetual smiles. The audience is encouraged to clap and sing, and punch the air, and finally invade the stage, but there’s not the space, or the time, or the health and safety permission, to fully let go and be as genki as our hosts. That’s part of the tease: being tempted by the toys and glitter, the lights and fleeting fame enjoyed by these bright young things, yet firmly held at arms length. But how I wished to be less of a spectator. I’ve no doubt Nikaido and her crew could make easy work of channeling an audience to properly be part of the action. Be careful what you wish for…