The Fantasticks, a long-running one-hit wonder for its authors Tom Jones and Harvey Schmidt, is the American Salad Days, which is probably why it’s never caught on here; we don’t mind extra dollops of charm, whimsy and melodic chirpiness as long as it’s our own.

I was once beguiled by the piece in the Open Air, Regent’s Park, but this new Japanese production, featuring eight resourceful British actors, two pianists and a box of props, is a bit of a struggle. The more they smile and caper, the more you feel like, well, stepping on their kumquats.

Thanks heavens for Edward Petherbridge and Clive Rowe. The first does some of his sweetest, silliest clowning as the old actor, ably assisted by Paul Hunter of Told by an Idiot. And the second is one of the two fathers – the other is David Burt – who create a false division between themselves to make sure their respective children fall in love.

Yes, folks, that’s the plot and it’s sort of over by the interval, bar a few scrapes and kidnaps, but nothing to make you glad you’re not reading Don Quixote. The best song, “Try to Remember”, is soon done with and the next best song, “Soon It’s Gonna Rain”, makes you wish for a deluge to wash them all away down Catherine Street.

The main problem with Amon Miyamoto’s production is the Stygian gloom of the black design by Rumi Matsui: the actors caper on a small black diamond in a black surround. The stripped-down, bare boards credo of Peter Brook is evoked in a programme note, but Brook’s Spartan gym for A Midsummer Night’s Dream was all-white, which makes a difference; and it really was designed by Sally Jacobs. This show is just put on a stage.

Lorna Want and Luke Brady sing well, and are not too ingratiating, as the girl and boy, while Hadley Fraser has charm to burn as the narrator. What exactly Carl Au is doing as the mute is anyone’s guess, but he does it gracefully enough. And there are 12 customers sitting on tiny bleachers on the stage, too. Let’s hope they don’t soon start outnumbering the customers sitting in the stalls, but it might be a good bet.