The Zetton group of restaurants has been known for showcasing its love of Hawaii through a series of casual and beach-themed restaurants in Waikiki: Aloha Table, Goofy Cafe and Heavenly.

On their tables are straightforward dishes highlighting locally sourced ingredients. The emphasis on sustainability hasn’t changed with the group’s newest endeavor, Zigu, a Japanese name translated as “eat local.”

But the sunny, beachy, shabby-chic vibe that drew the granola-and-acai crowd or loco-moco fandom to the other restaurants has been swapped for a more upscale environment suited to this sustainable izakaya and sake bar concept.

The food has become more sophisticated as well, drawing on the talent of chef Masaki Nakayama, who brings an intense umami quality to his dishes. It’s something he knows well, because his grandfather’s business was making katsuobushi, the dried, fermented smoked tuna used to create bonito flakes and soup bases that enhance food with that prized rich, savory note.

Nakayama spent two years working at Tokyo’s celebrated Tsukiji Market before going to school in New York City, where he studied kaiseki cuisine at Nobu Matsuhisa’s Katana, learned to work with wagyu and shabu-shabu at the Japanese steakhouse Celina, then made stops at highly rated Sushi Yasuda and Jewel Bako before opening his own restaurant, Mr. Robata.

At Zigu, Nakayama is able to bring all his skills to the table in a variety of dishes, from sushi to hot pots. Although it is only open for dinner now, lunch will be starting up soon.

The restaurant offers varied seating arrangements, from sushi counter space, to tables for two, a semiprivate back room for larger parties, to the open air of a patio. As at any izakaya, the more friends you have, the more dishes you’re able to try.

Start simply for an appreciation of the chef’s finesse at creating dashimaki rolled omelet ($7) of local eggs, the benchmark for any Japanese restaurant. Here, the soft egg is tightly rolled and there’s almost as much dashi as egg, filling each bite with a juicy pool of soup.

Another favorite starter is the potato salad ($7) with slices of applewood-smoked egg sitting atop the potatoes, as well as folded into the salad, giving it a deep smoky flavor.

Also not to be missed are morsels of deep-fried Kauai shrimp ($13.50) with basil-wasabi aioli. If you’re lucky, your friends will let you munch on the crispy deep-fried shrimp heads that bracket the dish.

Sometimes you read a menu and think there’s no way this could work, as I suspected of a salad of kinpira-style burdock with macadamia nuts and mango cream cheese ($6.50). It came as a pleasant surprise that it was actually delicious, the mango cream cheese presented as small dabs to stir in as desired, the touch of sweetness balancing the savory aspects of the shoyu-marinated burdock.

One of the showpieces, and what may become a trending food item of the year is roasted ahi kama cheek, the giant “tomahawk”-style cut prepared teriyaki style ($24).

Fish and chips ($15) gets a Hawaiian makeover when local white fish is paired with breadfruit chips served with shiso tartar sauce, while “laulau” ($13) gets a Japanese makeover when sweet soy-marinated kakuni-style pork belly is served over a small bed of luau, with a pair of macadamia nut- filled mochi balls.

In a few cases, more umami can be overpowering. Kona kampachi rarely needs much of an assist, but here it’s served with a thick sesame sauce that — while tasty — masks the delicacy of the fish. And a little saikyo miso goes a long way in a dish of grilled salmon ($19).

A handful of sushi options includes the Hawaiian vegetable roll ($11.50) as a vegetarian option comprising kale, braised Hamakua mushroom, lettuce, avocado, sweet pepper, cucumber and pickled daikon. There’s also a beautifully plated quartet of local ahi and Kona kampachi poke sushi ($12).

Some of the menu’s highlights are meant to arrive toward the end of the meal. These include hot pots of local pork, kale and ginger ($19) or romaine and chicken ($19). Both are excellent. With the former, the ginger is so potent that a few slivers are enough to flavor the entire hot pot.

Also meant to be enjoyed toward the end of the meal is a loco moco- like rice bowl of Pono Pork and omelet topped with cilantro ($13) and an intense ginger and turmeric curry served with 10-grain rice ($7).

The finale brings something new to Hawaii, housemade kale udon that is a perfect summer treat. The thick, supple noodles are served chilled with kale chips ($11), layered with cilantro and chicken ($15) or tossed with pesto and watercress ($13) for a refreshing summer salad.

This upscale endeavor is not the last to come from Zetton. Opening later this year is a Parisian cafe concept upstairs above Zigu.

Nadine Kam’s restaurant reviews are conducted anonymously and paid for by the Star-Advertiser. Reach her at nkam@staradvertiser.com.