For a restaurant to be successful, it does not always have to be the best. Sometimes, it is about finding the right niche and market.

For example, Ishi at the InterContinental Singapore Robertson Quay is a welcome addition to the dining scene here because it plugs a gap.

The food at the month-old Japanese restaurant is not as fine as in places such as Shinji and Hashida Sushi, but it is certainly more than a notch above many mid-priced Japanese eateries.

So it targets diners unwilling to pay $300 to $500 a person at the top restaurants, but who do not want to compromise too much on quality.

Ishi meets their requirements with omakase set menus that cost from $80 to $185 for lunch and $180 to $300 for dinner, with prices going up with the addition of more pieces of sushi.

There is also a $68 chirashi don set for lunch. And for both lunch and dinner, there is a small selection of a la carte dishes such as grilled wagyu and tempura.

My $180 dinner set comprises a small platter of sashimi, two hot dishes, seven pieces of sushi, a rice bowl, soup and dessert.

I add a Wagyu Beef Steak ($55 for 70g) to be shared between my dining companion and me and it adds up to a filling meal.

Head chef Masaaki Sakashita used to work at Hashida Sushi, so it is no surprise that the highlight here is the sushi.

If you have eaten at Hashida, you will recognise certain items such as the kamasu, or small Japanese barracuda, sushi.

The firm-fleshed fish is a highlight for me because its skin is scored and slightly torched to give it a pleasant smokiness.

The rice is not as flavourful as Hashida's and needs more acidity, but the fish is good.

What makes Ishi stand out is the spicy sushi. My set includes mackerel topped with mustard seeds that have a milder kick than wasabi and I like the way the tiny seeds burst in the mouth.

There is also nodoguro (blackthroat sea perch), which has a housemade chilli sauce - made with "tiger tail" chilli blended with koji and soya sauce and fermented for three months - tucked between the fish and the rice.

The chilli is only mildly hot, but the flavour profile is interesting and provides a refreshing departure from the rest of the sushi, which comprises more common items such as botan ebi (shrimp) and otoro (tuna belly) .

The sashimi platter, too, consists of mainly common items such as tuna and hokkigai (surf clam). But there is also kinmedai (golden eye snapper) that has been aged for four days and is bursting with umami flavour.

The two hot dishes - smoked kazu fish in ponzu sauce and sesame tofu with wasabi and uni - are okay but not outstanding.

So I'm glad I added the wagyu, which comes from Miyazaki. Each order has four thin slices that are grilled and served with freshly grated wasabi.

The well-marbled beef is worth the price and two slices a person are enough to complement the meal. Any more would be too much because of the fat.

But even without the beef, you do not have to worry about going home hungry, because rounding off the sushi course is a rice bowl topped with uni (sea urchin) and ikura (cured salmon roe) and a bowl of miso soup. If you like the two kinds of seafood, you will find little to complain about.

And to refresh your palate before dessert is a selection of pickles, including a chunk of zasai bought from Tokyo's Tsukiji market.

That is the Japanese equivalent of Chinese zha cai or Sichuan vegetable, the preserved knobbly stem of a mustard plant.

It is not as salty or spicy as the Chinese version, and is enjoyed on its own for its crisp texture.

Completing my dinner is a dessert of light tea ice cream sweetened with black sugar - a simple concoction, but one that leaves a pleasing impression.

So does Ishi. It may not be the best Japanese meal I've had, but it is satisfying. And while the bill is not low, I do not leave with the feeling that I am paying too much for what I get.

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• The Sunday Times paid for its meals at the eateries reviewed here.