Pssst! Wanna come to the loo with me? I've got something pretty startling to show you! It heats up, it cools down; treat it right and it sprinkles like a hose; it blows hot and cold…

Hey, come back! I didn’t mean anything like that. I just meant that the loo in this new Japanese restaurant, Saki, by Smithfield market, has one of those “washlet” lavatories that are as common as chopsticks in Tokyo, but are still a rarity in England. These loos – which dispense with loo paper in favour of a water spray followed by a hoot of hot air – are rare even in those Japanese restaurants here which strive to replicate the authentic Japanese dining experience; from the chorus of welcomes from kitchen and waiting staff as you enter, to serving the soup at the end of the meal (though, quaintly, not the Japanese practice of spurning tips).

Do you want to know the only sad part about the loo in Saki? It’s that it is not made by the Japanese brand leader, Toto, a company which, when I lived in Japan, used to market its washlet range of sanitaryware with the endearingly memorable slogan, “Your bottom will like it after three times. Don’t let people say behind your back that you have a dirty bottom.”

Maybe it’s just that Toto’s toilets aren’t compatible with British plumbing. A pity, because the consequence of Saki’s lavatory being made by a firm called Aspen rather than by Toto is that the labels on the cockpit-style control panels that flank the loo-bowl – a bit like the arms on an armchair – are written in English rather than in Japanese Kanji script.

Why should this matter? Is that what you’re wondering? Let me tell you why. Because this removes much of the bewilderment for a novice washlet user, who would otherwise have to stab buttons at random, not knowing whether to expect a cleansing sprinkle or a whoosh of hot air.

Frankly, this kills much of the fun. Perhaps the most common (and I’m using the word “common” here in its sense of “amusing”) mistake made by foreign men visiting a Japanese home is heading off for a wee at an unfamiliar washlet loo and, when they’ve re-zipped their flies, jabbing the console button they gamble might activate the flush – only to find a thin steel tube emerge from the back of the loo-bowl and launch an angled jet of cleansing warm water at where it calculates someone’s bottom should be. But there’s no bottom there. Just the man’s trouser-front. So then the foreigner must return to his hosts with a wet patch sprayed across the front of his trousers which, because the Japanese are very polite, nobody ever mentions again.

The Japanese have a reputation for being inscrutable. But they’re not inscrutable. It’s just that they’re too polite to mention to visiting foreigners that they have evidently pressed the wrong button on the toilet console and now have a large damp patch on the front of their trousers. Japanese, for their part, are just as mystified by foreign behaviour; particularly why it is that no foreign scientist seems to sit in his laboratory and think to himself: “Now that I understand pretty much everything about quantum physics, nuclear fission, atom-splitting and cosmology, I think I’ll devote my life to designing the perfect bottom-spraying lavatory.”

Belatedly, perhaps, gadget enthusiasts are trying to bring these kinds of innovations to more British households; along with fridges that send you an e-mail at the office when you’ve run out of milk, and central heating systems that tap into the weather forecast and adjust all the thermostats accordingly. One day soon you’ll be sitting in a bar and your mobile will ring and you’ll be saying, “Really? It’s very acidic? With evidence of protein?” That’s a strange time for your doctor to be calling, your friend will remark. And you’ll explain that, “Actually that was my lavatory: it has just completed a chemical analysis of my morning ablutions.”

Often Japanese restaurants, even those serving wonderfully fresh fish, can be rather uninviting: pine tables; bright lighting; functional, rather than places to linger. And since, generally, Japanese food comes in modest portions, there might not be much reason to linger anyway. But Saki is housed in an attractive room: maroon walls, dark wood tables, subtle lighting. The room’s curious centrepiece is a square white gravel pit, from which rise what may be stalagmites of white crystals; only they seem to have wicks peeping out of the top of them. There is a separate bar to one side; and a shop upstairs, though it is closed in the evening.

You scan the menu and – hooray! – no black cod with miso, a dish whose ubiquity must strike Japanese tourists as perplexing, given its modest profile in Japan itself. It’s like walking into every English restaurant around the world (were there such things) and seeing on the menu “roast beef with ketchup”; hmmm, interesting, but hardly a kitchen staple in England.

On the downside, Saki’s menu succumbs to comparing its starter dishes to Spanish tapas. Just as areas of land in documentaries are always measured in multiples of Wales, and volumes in multiples of Olympic swimming pools, restaurant food is now calibrated in tapas. In Indian restaurants, samosas and onion bhajis and cubes of chicken tikka become “tapas-style Indian snacks”. Dim sum becomes Chinese tapas. Taramasalata and hummous evolve into Greek tapas. Lebanese meze are reborn as Middle Eastern tapas. Italian restaurants struggling for modishness rename their bruschetta tapas. The only fancy restaurants where tapas are hard to find tend to be Spanish restaurants. One day – perhaps when fish and chip shops rename pickled onions and saveloys “seaside tapas” – fashions will finally move on and tapas will be so yesterday that even Spanish tapas bars will be re-christening their small plates of chorizo “Spanish dim sum”.

The food itself is pretty sprightly, though. Chicken yakitori skewers, enlivened by spring onion, were as good as any you’ll find in Japan, arriving with an authentic layer of moist, fatty skin. Slivers of octopus carpaccio (carpaccio? Carpaccio is rather more Nobu than Nippon) is doused in a delicious and delicate sauce made from blitzed shiso leaves and chilli. It was sensational; though, at £7.90, it was served in a portion that would allow the kitchen to stretch a single octopus to feed most of Tokyo. Chawan-mushi, a savoury egg custard that can be a litmus test of a Japanese kitchen’s skills, had a flavour that pulled off that Japanese trick of toeing a precarious tightrope between exquisite subtlety and so-whattish blandness.
Chirashi sushi – planted in a section of the menu headlined “Carbo” (apparently to denote “carb-up dishes”, such as rice and noodle-based items) – was more elaborate than you often find it. A common lunchtime dish, this is usually a deep round lacquerware bowl of sushi rice covered with slices of raw tuna, from which you mould your own makeshift sushi with your chopsticks. Here it was a small, conical ricebowl, crammed on the surface with an assortment of raw fish, making it more elaborate than need be; and trickier to eat. Tasty, though.

Tempura arrived in a paper-thin batter, ungreasy enough to allow it to soak up its accompanying dipping sauce: often it’s like chip-shop batter. Japanese food is not as tricky to produce as some pricey Japanese restaurants like to make out. Becoming a sushi chef might officially require seven years’ training to learn how to hold a knife, how to sharpen it, and at precisely what angle to slice the fish. But you can do a reasonably adequate job at home if you have a decent fishmonger nearby, especially now that Japanese ingredients and condiments are more widely available. Tempura shouldn’t be beyond anyone who is happy to deep-fry in their own kitchen. The food at Saki is good, but at £60 or so a head it ought to be. You could eat at least as well for a third of the price in any neighbourhood New York Japanese restaurant.

Still, staff in this new restaurant are eager, willing and helpful; if still a little inexperienced. A different waiter drops by every 40 seconds to see if you are ready to order, unaware that they are the fourth to do so: they are only aiming to be attentive, but it can feel like pestering. Of course, if the pestering gets too annoying, you can always escape to the loo. That sensation of hosing your haemorrhoids might feel strange at first. But remember: your bottom will like it after three times. Toto swears so. And nobody will be able to say behind your back that you have a dirty bottom. That’s a bonus in anyone’s language, isn’t it?

Saki
4 West Smithfield, EC1 (020-7489 7033; www.saki-food.com)
Open for lunch and dinner, Monday to Friday

Giles Coren returns next week

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