In the words of the sultry pop combo Sugababes, push the button ...

Set in the desk-like seating area beside Yo! Sushi's conveyor belt are the sort of mad-scientist red buttons that beg to be pressed. Do so, and you'll be startled by the electronic bark of what appears to be Professor Stephen Hawking's second cousin from Yokohama, summoning - and in no uncertain terms - assistance from the black clad waiting staff.

And they spring into action with true Japanese efficiency, even if none appear to hail from the land of Tamagotchi. (The sushi chefs, on the other hand, appear to be the real deal as they silently prepare the meals nearby.) Yo! Sushi having had several weeks to get its chopsticks in order, my friend and I felt it was time for an appraisal.

We were denied a table as YS insists on a minimum of three diners occupying these in the evenings, so we perched on the low-backed stools - which weren't quite as uncomfortable as they looked.

WHAT'S THE PLACE LIKE?

It was busy on a Thursday evening at 8.30pm; our fellow chompers were mostly in their 20s and 30s, looking tanned and confident. Before you sneer that sushi's just for posh folk, remember that as of this week, Butlins has opened its first sushi bar at Bognor Regis (and it costs £7.95 to enjoy a 10-piece platter of gunkan, smoked salmon nigiri and tuna maki rolls!).

Back to YS. The restaurant design is Bacofoil chic, with air ducts and shiny metal components gracing the ceiling.

Video screens on the walls flash up images of oriental food while small bowls slide past in a parade of half a dozen colours (they correspond to different prices, from £1.70 to £5; your total is totted up at the end). The food isn't all raw, and it's not all fish either.

HMMMM. CAN I EAT THERE WITHOUT BUSTING MY OVERDRAFT?

Yes, but only if you keep your wits about you. Follow the Guide's credit crunch commandments and remember the letter B: 1) BEER: It's very expensive (nearly a penny per millilitre), so don't order much, especially as if you're tipsy you'll end up 'grazing' without thinking. Asahi on draught is £4.60 per pint, while the £6 tag for a curvy silver 660ml can will make your eyes water like you've rubbed wasabi sauce in 'em.

2) BOOKLET: If you're a rookie, consult your desk pamphlet. It tells you what's available off the belt and what you can order separately (such as the intriguingly named 'hairy prawns').

3) BOWLS: The cheapest colour is green, but these dishes aren't up to much, while grey is extravagant. Go for blue, pink and orange; choose grey and purple sparingly. Incidentally, mundane doesn't always mean cheap - marinaded aubergine costs more than beef nigiri.

4) BLAND: Avoid the rice-based nigiri pieces; they're often dull and Tesco's versions are far cheaper.

5) BOXES: YS takeaway boxes work out at half the price of eating in.

WHAT DID YOU ORDER?

Salmon, hamachi and tuna fillets; octopus slices on rice; chilli squid with salad; edamame beans; crayfish salad; chocolate dessert. The fiery chilli squid was the clear winner, while the octopus was absolutely rubbish - chewy and devoid of taste. As for the lukewarm chocolate mousse, there's a reason why Japs aren't known for their puds.

We didn't order green tea and miso soup, but it's worth knowing there are free refills on these sundries.

WHAT WAS THE SERVICE LIKE?

Polite, friendly and unobtrusive. We were surprised that we didn't get hassled to eat up and make room for more punters. Mind you, for some reason, at about 9.30pm, folk around us started leaving like there was a curfew. Was it something we said?

VERDICT: Yo! Sushi is enjoyable, but a triumph of style over substance. It's hard to know why it's so expensive - especially when surely the firm is saving on cooking costs?

THE BILL £40.30 (includes four pints of beer at £4.60 each)