KOYN in City of London, Westminster

I am extremely disappointed with the experience my party and I had at KOYN last night. We made a reservation for a group of 12 and were initially greeted warmly, which gave us high expectations for the evening. Unfortunately, things went downhill quickly, and our experience turned out to be far from what we anticipated. One of the most troubling aspects of the evening was that we were refused drinks at one point, being told that our group was too noisy. However, we were not creating excessive noise bar what a usual table of 12 would produce (I even took a video as evidence). Even more concerning was the rude and unprofessional attitude of the blonde lady at the front desk. Her tone left me feeling disrespected and frustrated. In addition to the poor service, the quality of the menu was a significant letdown. For the £110 per person menu, we expected a much higher standard of food and variety, but the dishes offered fell well short of our expectations. As hosts, we were embarrassed to have invited 10 of our most valued partners for what we hoped would be an enjoyable dining experience, only to be let down by subpar treatment and a lacklustre meal. This is not the impression we wanted to leave with them, and I can only hope it hasn't reflected poorly on our business. I hope KOYN takes this feedback seriously to prevent future occurrences. We had high hopes for this event, and it’s unfortunate that it didn’t live up to the reputation we expected.

From the moment the gentleman at the door (I think Don ) opened the door with a smile and we were greeted by Nathan who was just so lovely and non pretentious, we knew we were in a great place. We did not even have a reservation and it was Friday night and Nathan made us feel so welcome until he found a spot for us to seat. Mariana who took us to the table and Redina who guided us through the menu were all absolutely delightful, we even got to speak to the head chefs Salvatre and Jacki and we were sat watching the kitchen fireworks and hard work. The food was sensational and I can not wait to go back ! Thank you Nathan for letting us in with such a warm welcome.

I love this very wholesome restaurant in the middle of Mayfair. From the decor (inspired by Japan’s summits on the top floor and Thailand’s craftier more handmade nuances on the floor below), to the perfectly spiced crab Thai curry, delicious cocktails - Koyn Thai is delightful for a night out with friends or family. Wholesome plates that don’t pretend and service that’s warm and hospitable - love!

Incredible food, incredible presentation! I can’t even begin to describe it, you just have to visit Koyn and experience it for yourself!

I went the week of opening with 3 friends and we were all mazed by the flavour and quality of food. it's not for the faint of heart, as the dishes pack a punch - but the team is lovely and will guide you through the menu, advising you on spice/ hotness level for all the dishes. The pomelo salad, crab cakes and massama lamb curry was exceptional - and make sure to end your meal with the sticky rice mango pudding! Can't wait to go back!

A fantastic addition to the Mayfair culinary scenery. As a regular in Koyn (Japanese) I could not miss the opportunity to try their newest project. Thai sister, located in the basement of its older sibling definitely did not disappoint. Not only the food and service exceed expectations but the price point for the locations is extremely encouraging. Whatever you are ordering, make sure you don't miss on the squid (the best I ever had), pomelo salad (an example of how simplicity perfectly executed can mean perfection itself) and grilled pork neck (just WOW)

We love Japanese food but we always go to the same places when we visit London so this time we went off piste and went to Koyn and what a nice surprise it was ,great service and a couple of outstanding dishes the smoked sea bass is wonderful and the Wagyu beef was amazing . Yes it’s expensive but when the chef Rhys Catermole takes the time to come and talk to you about your evening you know you are in good hands and you know it will get even better , and just to make it even better Adam Sandler was there as well.

Outstanding service, outstanding food and an outstanding experience. Loved every second of our visit, from the atmosphere to cocktails, service and food. Everything we ate was excellent. I’ll be back as soon as possible!

Visited the bar for drinks and nibbles with friends. We all had 2 G&Ts each @£22 each, two (very delicious) chicken wings each and one piece of vegetarian sushi (fried rice they call it) and paid £60 each. We were all very surprised to find out that even though the bill included a 15% service charge, the card machine was asking us to add extra service charge. The bar was ok, nothing amazing. The martinis were absolutely minuscule (the size of shots) and they didn’t stock any bourbon (just Japanese whiskeys and a very small selection of Scotch like Johny Walker). Noticed a couple of working girls at the bar, but that’s typical of anywhere you go in Mayfair these days. I don’t think we’ll be returning.

Had a great dinner! Had great service by Niki with my food allergies and would highly recommend. Niki was super attentive, great food and great service

I had the distinct privilege of dining at a Japanese restaurant in the heart of Mayfair, London, with high expectations, especially with the renowned Sexy Fish just around the corner. To say the least, my visit was an unforgettable experience, albeit not in the way one would hope. Our adventure began with seating placement that can only be described as strategically positioned by the entrance, affording us zero view of the culinary theatre. This was merely a prelude to the gastronomic disappointment that was to follow. The diced "ceviche" we dared to order bore no resemblance to its namesake. It was, without question, a culinary misadventure in the world of seafood. Our encounter with fried squid was further marred by a mayonnaise concoction that, if anything, intensified the misery. Desiring a dash of chilli sauce to rescue the dish, we inquired about the availability of chilli sauce, only to be met with the incredulous response that the chef was incapable of dicing chillies. The result? A plate of insipid, haphazardly sliced chillies presented before us, accompanied by an unexpected charge. The Crispy Rice with Spicy Tune, in a tragic twist of fate, did no justice to the tuneful fish it once was. It was an elegy for the culinary potential that had gone unfulfilled. Amidst this sea of mediocrity, the Jumbo Tiger prawn emerged as a singular beacon of hope, offering a delightful respite from the culinary quagmire. However, the lamb cutlets, sadly, were as basic as they come, failing to rise above the mundane. In conclusion, my experience at this establishment left me with an indelible impression, albeit not one that inspires repeat visits. It was a trifecta of financial regret, time wasted, and culinary aspirations dashed. Suffice it to say, my appetite for returning is as non-existent as their ability to properly dice chillies. Bon appétit elsewhere!

10/10 Japanese food. Everything we ordered (which was a lot!) was all impeccable. Service was brilliant, in terms of attentiveness and friendliness. The A5 Wagyu Koyn Senbei was genuinely mind blowing! The reason I give Koyn 4/5, is because we went on a Wednesday night and I felt the restaurant lacked a vibe (we were sat upstairs), however, downstairs was not open the evening we visited but much more vibey so I would recommend being seated downstairs if you can. MUST ORDER: Wagyu Koyn Senbei, Tomato Tartare (trust me!)

The food was well below average, no dish was tasty or anything to write home about. Given the other restaurants by the same owner are much better, this was a sore disappointment. Not to mention, it is highly over-priced.

We visited on a Sunday night. Although it was bank holiday weekend, the place was not too busy. Much of the upstairs section was occupied, but the downstairs area was closed off. The decor is upmarket and in line with what you’d expect in the heart of Mayfair. The two of us ordered the spicy edamame, wagyu gyoza, rock shrimp, tuna tartare, black cod, lamb cutlets, broccoli and 2 sets of sushi rolls. For dessert we tried the yuzu meringue and chocolate fondant. The food was solid, we enjoyed pretty much everything we tried although not much really jumped out. Service was ok-ish. Friendly but disorganised at times. The bill for the 2 of us came to £475, of which £185 was spent on drinks. This felt a bit excessive, even if considering the neighbourhood. Overall this was a pleasant meal in an upmarket setting, but somehow the experience felt dull and forgettable. The atmosphere was sterile, and the other guests seemed to be more tourists than Londoners. There are myriad of options in town serving almost identical menus (Nobu, Zuma, etc.) and a lot of them are cheaper than Koyn while offering a better atmosphere and similarly good food, so I’d recommend going elsewhere for a contemporary Japanese meal!

KOYN is a pseudo crap restaurant that misrepresents fine Japanese dining. Japan has one of the top Michelin star dining experiences in the world and there is a reason for that. Very fine taste, quality, and presentation. It’s expensive but every penny of that is worth it. KOYN is loud, has not many Japanese (therefore lacks authenticity) and is a rip off. Save the children somewhere else or spend on something more real. Unless you like pissing your money away

I cannot fault the quality of the food. It was sublime. And the desserts at the end did not disappoint. Compliments to the chefs for a thoroughly enjoyable evening.

We booked a table for 6 people on the 10th March for 6 people at 6:15pm. We had a last minute unexpected guest. So we were 7. The staff then proceeded to tell us we need to spend a a minimum of £150 per head. Considering only two us drink alcohol and there were three kids this is the most ridiculous policy I have ever heard. We even suggested that the adults, 4 of us, sit on one table and the three kids (young teens), sit on another table and we pay two bills. This was point blank refused. I hasve never heard of this in my life. Credit card for the booking, charges for last minute cancellation - fine. This is taking restaurant Nazism too the next level. Will never return. What a joke! We got up and left and went to Me Me Mayfair Chines which was excellent and who were accommodating!

A Hollywood director and internationally renowned TV Producer invited us to a private dinner at a seemingly well rated Japanese fusion restaurant KYON. DISASTER…..TERRIBLE FOOD…..noisy like hell and RUBBISH wrapped in a fancy bundle!! Ever heard of a micro cigar sushi roll that doesn’t even feed a kitten priced at close to £15 and maybe 25g of wagyu for £84. Neither, fun, tasty, novel or beautiful. It’s RUBBISH. You’re better off at McDonalds for a beef burger. The worst part was trying to fake Asian with a chinese waitress.

The venue is well designed but outrageously expensive for mediocre menu. You are simply paying for the interior designer and the location. You are definitely not paying for a wow factor experience for a Japanese restaurant. A glass of Chianti sets you back £12 when others restaurants in Mayfair charge £6/8 by glass. The menu is minimalistic as the interior design concept.

Excelente restaurante japonês , requintado e decorado com requinte , excelente serviço e uma comida diferenciada . O preço como todo restaurante requintado é caro , vale a pena sim

Being a new restaurant we had high expectations and as we couldn’t get a last minute booking elsewhere we were pleased to get a table. The service was excellent - we had a wonderful table downstairs. The decor was great. We are vegetarians so have a high expectation that unfortunately were not delivered in the quality and taste of the food. We were left rather disappointed. I hope that over time they will improve the taste of the vegetarian food and will wait another six months before venturing back!

As a family of six (2 teenagers), we really enjoyed our evening at Koyn. We loved the atmosphere downstairs, knowledgeable and fun waiting staff - Nicky ? Should also say the Vegetarian food was delicious. Will definitely return, thank you and Merry Christmas from us...

What a delightful evening,spectacular food the wagyu steak Alaskan crab etc etc were outstanding,,,perfect ambience outstanding service unarguably one of the finest Japanese restaurants in london a must must visit !!

Visited at lunch time. The welcome received and ambiance of this place is excellent. The menu is interesting, bold and very varied. We had the Chu Toro, the rock shrimp, Chilean Seabass (this is delicious) the baby chicken, lobster roll amongst various sides. All were...

Nice starters. Very poor Sushi and sashimi. They may have ordered it delivery from a fast food sashimi joint. Service needs training in hospitality. Seems they all trained on a commission based trading floor trying to maximise your bill.

A fantastic overall experience, with delicious food and atmosphere! A bit on the pricey side, but all in all worth it, especially if there is a special occasion to be celebrated.

We had an amazing dinner at Koyn - the head waitress, Nicky, was so knowledgeable and the food she recommended incredible.

Probably we are old fashion but we still believe that Japanes Restaurant must have something special that only real japanese have. It' s about the sacrality, gesture, autenticity, quality......in this place there is nothing true. Indian owner, chinese sushi, mixed europea staff loud music. They...

I visited for dinner with my partner. The staff was always ready to help and well knowledge , the design and every single details are stunning , the atmosphere is lovely, and the food is both delicious and beautifully presented.

Our last night in UK after 3 week visit. We discovered this brand new restaurant (literally two weeks old). We had a wonderful meal with much thanks to our exceptional waiter Daimi, who recommended a diverse, to be shared set of salads, starters and mains....

Koyn just recently opened on Grosvenor Street. Great location in Mayfair. I love Japanese food, and there are plenty of options to choose from in London. This is an outstanding addition to that list. And as far as quality of food, amazing décor and lovely...

I went to Koyn for the first time to try it out. I went with my friends to celebrate a birthday. Beautiful cocktails to start from the friendly bar staff. Food and wine recommendations were spot on in the restaurant. Amazing atmosphere, spot on service....

Really enjoyed my evening at KOYN. Firstly the restaurant is absolutely beautiful, the staff were really friendly and welcoming. The menu variety what great! I really enjoyed the sushi, tiger prawn and lobster dishes. Everything was so tasty and flavours on point. I finished with...

The restaurant has great décor and ambiance, beautiful location. The service was very attentive , waitress had great recommendations and had knowledge about what the restaurant is serving. Really enjoyed the food everything was full of flavors. Bar did great with signature cocktails. Thank you,...

I had such a great time here with my family, the food was delicious and beautifully presented, warm service and beautiful interior design to add! Understated and elegant! Thank you for giving us such a memorable experience.

Such a lovely experience. The staff made the experience really enjoyable. They were so helpful from start to finish., offering great advise and going above a beyond to help me find the signatures on the menu that i would like. The food was great the...