After my first visit to Katsu in Los Gatos, I was so impressed that I invited a friend who is a student of all things Japanese to go along on my second dinner. I knew she'd appreciate the freshness of the ingredients and the textures and flavors that chef Katsuhiko Hanamure, the restaurant's namesake, incorporated in the dishes.

That first meal, while not perfect, was good enough that I would gladly order each thing I tried again. The firm, rich flesh of the hamachi ($16) was highlighted with a sauce of tangy yuzu citrus and jalapeño; the sesame scallops ($25) were fat and succulent in their crisp tempura batter, and the sauce was delectable even though it had broken.

The second visit was marked with inconsistency in the kitchen, frustrating issues with timing and an atmosphere more like a nightclub than a fine dining restaurant.

Upon entering Katsu, you feel immediately transported to a Las Vegas club. We remarked upon that during our first visit on a subdued Sunday. Our Saturday night visit cemented that impression -- the music was near-deafening and the tables were filled with partyers.

The trendy, attractive space is a study in purple. The high-ceilinged dining room is bathed in lavender light, windows are draped in floor-length aubergine velvet, and seating is in plush violet-colored chairs and banquettes. One wall is covered with gleaming Mondrian-inspired panels. The large bar is a glittering mosaic from which you can order an overpriced cocktail. Most signature cocktails range from $15 to upward of $20, unless you're there for happy hour.

Chef Katsu has some pretty impressive credentials, most notably as a protégé of chef Nobuyuki Matsuhisa, the renowned chef known as Nobu. He worked his way up to sushi chef, then executive chef, at five restaurants in the Nobu empire.

Nobu's influence is evident, as Katsu's menu is a fusion of global flavors and technique, particularly in his use of Peruvian flavors. In the HK47 tuna ($20), served over a fried cube of sushi rice, the Peruvian spices had a heat that grew to a pleasant burn -- making this the best of what we tried on that disappointing second visit.

That night, we nibbled on corn fritters ($12) and sipped cocktails while deciding what else to order. On my first visit, the sweet kernels of corn were held together by a savory, barely there batter with great flavor, but two fritters were almost baseball-sized, which meant undercooked batter in the middle. On this visit, the fritters were uniform in size and shape, but the batter lacked the delicious umami quality of the first batch.

The menu generally is divided by provenance of the food (sea, land and garden) with separate sections for sushi and chef's specials. We ordered the HK47, unagi (eel) ($9), and ikura (salmon roe) nigiri ($8) along with our main courses, the duck breast ($24) and salmon in a spicy miso sauce ($26).

Somehow, perhaps because of the din, there was a miscommunication. We had intended to eat the HK47 and nigiri as a separate course before the main dishes. Instead, they arrived along with the salmon, but inexplicably not the duck, which came several minutes later. Frankly, it was overwhelming to have all those dishes on the table at once.

The flesh of the eel was mushy, and the ikura so large it couldn't be eaten in one bite. What the duck lacked in flavor it made up for in gristly bits running through the middle. The salmon was devastatingly overcooked, which was too bad because it looked like it was once a quality piece of fish. The miso glaze had good flavor, though.

There are bright spots on the menu. The A-5 Wagyu carpaccio, a splurge at $30 for less than 2 ounces of beef, is pure luxury. Made with real Japanese Wagyu rather than the more commonly found American-style Kobe beef or Australian Wagyu, the richly marbled slices of beef nearly melted in my mouth. Bursts of complementary flavors and textures came from capers, pomegranate seeds, ginger and daikon.

Dessert was a pleasant surprise. It's easy to see why the banana spring roll ($8) is the most popular choice. Rice paper wrappers are filled with banana and deep fried, then drizzled with chocolate and served with housemade vanilla ice cream. Red velvet cake ($8) is uncommonly restrained in sweetness with a raspberry filling and light frosting. A duo of homemade mango and pineapple sorbet ($6) was light and refreshing but very icy -- more like granita.

There's a real desire among the staff to please. When we pointed out a lipstick-stained water glass, it was apologetically removed and replaced in a flash. Once, my gaze must have lingered a few seconds too long where a manager stood at the bar because he high-tailed it to our table to ask if everything was all right.

It's this attitude that gives me hope for Katsu. The clublike atmosphere is what it is. This is a place for celebration rather than conversation; a place of revelry, not romance. But some work on the timing of the service and, more important, consistency in the kitchen could make Katsu worthy of another visit.

Email Jennifer Graue at features@mercurynews.com.

Katsu

* ½

Address: 160 W. Main St., Los Gatos
Contact: 408-354-0712; www.katsulosgatos.com
The Dish: Upscale and trendy, Katsu offers Japanese fusion cuisine in a Vegas-like setting.
Prices: Sushi, nigiri and sashimi, $6-$25; small plates, $8-$30; main courses, $24-$125; desserts, $6-$9; wines by the glass, $8-$25, and by the bottle, $30-$250; cocktails, $13-$25
The Details: Chef Katsuhiko Hanamure's menu is greatly influenced by his mentor, Nobu.
Pluses: Those in the market for a splurge will find real Japanese Wagyu on the menu rather than the American and Australian impostors. Katsu also offers happy-hour specials with many drinks and menu items offered at half price from 5 to 7 p.m. weeknights and noon to 4 p.m. Sundays.
Minuses: The kitchen is inconsistent in the execution of the dishes. If there's a crowd in the restaurant, it's going to be loud.
Hours: 5-10 p.m. Monday-Thursday and until 11 p.m. Friday-Saturday; 11 a.m.-
8 p.m. Sunday, with brunch menu served 11 a.m.-3 p.m.
Restaurant reviews are conducted anonymously. The Mercury News pays for all meals.