Izakaya? O Yes

In Japan's informal, convivial izakayas, groups of friends or co-workers gather around a table for a few hours, knocking back large quantities of beer, sake, wine, shochu (sake's distilled cousin), whiskey, and/or cocktails while fortifying themselves by sharing small plates of booze-friendly food. In recent years, izakayas have become very popular in New York and Los Angeles, but despite San Franciscans' fondness for shared small plates, Japanese food, and alcohol, the trend is just getting started here. The three-year-old Oyaji, which has an izakaya menu and bills itself as one, hedged its bets by also having a sushi bar.

No such waffling is going on at O Izakaya, which opened last November in the Hotel Kabuki's large Post Street restaurant space, former home of Dot, Lord of the Balls, YoYo Bistro, and Elka. Except for an incongruous burger, the menu consists entirely of dishes intended to be shared, organized roughly in the traditional sequence of an izakaya meal: cold shared plates (sashimi and salads), agemono (fried items), yakimono (grilled items), hot shared plates, soba noodles, rice, miso soup, and pickles.

The menu is relatively sophisticated for an izakaya, and the space is decorated to match, with lots of lacquered wood; soft, warm lighting; and coasters and window shades printed with images taken from Japanese baseball cards enlarged so greatly that you can see the dots in the halftone screen, like a Roy Lichtenstein Pop Art painting. The music is unobtrusive and, even with a noisy, drunken crowd at the central bar, conversation is easy in the comfy booths lining the walls. The servers and bartenders are so friendly you can easily forget you are in a hotel, at least until you have to walk out of the restaurant and to the far side of the building to find the bathroom.

The first concrete sign of the kitchen's ambitiousness is the arrival of an amuse. On one visit, this was a small bowl of delicious nettle soup with trumpet mushrooms. The thick, dark green liquid was reminiscent of matcha tea, but with intense aromas of nuts and caramel. I would have had no clue what this synergistic, alchemical concoction was if the server hadn't spelled it out. On another visit, the amuse was a diver scallop tartare with diced fennel bulb and a bit of fronds, a surprisingly nice combination.

Yakimono, grilled items, are great cheap bar snacks and the strongest section of the menu. My favorite was the pork belly. Crisp, moist, smoky, and fatty, it was augmented nicely by the hot pepper mix served with all the yakimono. I don't think I could eat here without ordering this. Meaty duck hearts were cooked perfectly so they stayed juicy. Beef loin was nice and rare. Slightly sweet, golden-brown rice balls (omochi) were crunchy outside, creamy inside, and a bit bland until spiked with a sprinkling of hot pepper and a squeeze of lemon. Tender honeycomb tripe was taken off the skewer and served in a bowl dressed with sauce. Chicken thigh was the least interesting of the batch, but still good. My one complaint is that the pieces of beef and tripe were so big they were hard to eat with chopsticks; next time I'll ask for a knife and fork.

Agemono, fried items, were a mixed bag. Fat onion rings in a thick Black Butte Porter beer batter were hot, crunchy, well seasoned, and great with the accompanying aioli and ponzu. The same thick batter didn't work nearly as well with mushrooms as a traditional thin tempura batter would have, though the hatcho miso offered as a dip was a clever idea. French fries sprinkled with shichimi (a Japanese spice mix that includes chileand sansho peppers, among other items) were nicely crisp. "Butternut squash tempura" is a grossly misleading description; the dish proved to be a deep-fried sushi roll with a cream-cheese center, the squash diced finely and mixed with the rice. Too bland by itself, it was made passable by a dip in the ponzu and a sprinkling of a mix of green tea and salt, but the dish was still disturbingly reminiscent of TGI Friday's.

Fancy "cold shared plates" took the place of what in a more traditional izakaya would be sashimi. Five small slices of saba (cured mackerel, laid on a bed of thinly sliced cucumber and red and yellow beets, and topped with grated ginger and wasabi), were beautifully presented on a long, rectangular glass plate, but $13 seemed a steep price for less fish than I got last week in a single order of saba nigiri sushi. Seared albacore with tonnato sauce (tuna mayonnaise) and a salad of mizuna and shaved bottarga was more food and better value, but the dry fish was not as good a match for the tonnato as the grilled beef.