For a just-opened Japanese restaurant/fancy cocktail bar located several storefronts away from the bustle of First Avenue, NR doesn't seem too worried about letting its new neighbors know that it exists. The only notice outside is a small, cryptic "NR Open" sign on the dark wooden front door (the name stands for "'n Roll," and also "Non Resident," and, one more: "No Regrets"), and a kind of plastic scrim on the windows makes it difficult to visually determine why you should care at all.

Ah but once inside you won't soon forget about this place, especially if you're tired of the cookie-cutter family spots and bro bars that dominate the scene in this part of town. NR is the second restaurant from Shigefumi Kabashima—who also owns and operates ROKC in Harlem (that acronym at least makes sense on its own: Ramen Oyster Kitchen Cocktail)—and he really set about amping up the romance in this former Seamstress space.

There are marble and wooden tables, blue fringe lamps, paintings, raw brick, random wallpaper, and two long banquettes. The dining area is divided in half, so it seems more intimate than the 120-person capacity might suggest, and there's a convivial scene at the bar. The soundtrack is jazz and swing, it's dimly lit and rustic, warm and comfortable, and it feels like a secret.

As at Kabashima's ROKC, a lot of energy at NR is devoted to the cocktail program, with 21 original creations each served in one-of-a-kind, often quite elaborate "drinking vessels." Non-booze ingredients in this part of the menu include things like pistachio cream, strawberry jam, Thai tea, beets, truffle honey, and Parmigiano. There are also classic cocktails, highballs, wine, beer, and sake. The bartender invented a citrusy, non-alcoholic concoction for me on the spot, and it was bracing and delicious.

NR's food menu is more concise, but it's all appealing and you can easily grab a couple of drinking nibbles or devise a full meal. I ate most everything earlier this week, compliments of the house, and there is much to recommend. The best dish turned out to be "Mussel + Beer + Cotton Candy," which sounds ridiculous but really works, a warm beer-based broth poured over a dozen or so plump, tender mollusks, melting the sugary puff of candy on top, a yuzu zest providing a nice counterpoint to all the yeast and brine. When you've finished picking through the mussels you'll want to pick up the bowl and drink it to the lees.

Yuzu is also used to good effect with the steam-basket of Edamame, enlivening that somewhat utilitarian snack. The Melty Pork Bun delivers on its sticky, piggy promise, and the serving of Kaarage, or Japanese fried chicken, is impressively large for under ten bucks, with four fat, juicy pieces falling out of their crisp-fried skins. The accompanying crock of matcha salt is a thoughtful touch. The Oyster of the Day sells for $1.50 each.

Two types of ramen round things off. There's a Vegetable version with noodles, mushrooms, corn, seaweed, scallions, and pink peppercorns all floating around in a kombu and shitake broth; and the Kyoto, which I slurped up with pleasure, starring pork belly, egg, spicy bamboo shoots, and garlic and chili oils in a rich soy, chicken, and fish broth. Both of these are robust enough to satisfy as entrees. At the end of my feast I was given a dish they're working on for the near future, an Egg Sando paired with a crock of clarified butter for dipping, which I hope will become a trend.

The inspiration for NR, apparently—the food, the drinks, and space itself—is the Meiji period of the late-19th century Japan, a time when Western influences started popping up in port-town restaurants on that island nation.

NR functions well as a neighborhood go-to, a place to catch up with friends over drinks, and, maybe especially, as a second- or third-date spot. Given its low profile from the street, it should remain quiet and cozy for at least a little while longer.

NR is located at 339 East 75th Street, a little ways west of First Avenue, and is open Sunday through Thursday from 5 p.m. to midnight, and on Friday and Saturday from 5 p.m. until 1 a.m. (