Summing up a restaurant in one word is a tough task, but Umi Sake House makes the job easy.

This place is fun.

Umi, secreted away between Belltown's Flying Fish and The Apartment, is the recent makeover of Bada Lounge. Last spring, owner Steven Han closed his deep, dark, Pan-Asian restaurant and club and re-envisioned it as a sprawling hangout built to resemble a Japanese home. Hai!

The new layout is a palate-pleasing playground complete with sushi bar and lounge, a glass-enclosed tatami room and a sky-lit dining area whose low tables and two-tush futons are shaded by weeping fig trees and Japanese maples.

Han is among the first, locally, to jump on the izakaya trend now taking off in cities like New York and L.A. In Japan, those casual restaurants are popular spots meant for grabbing a drink and a bite and their menus feature a variety of shareable small dishes. At Umi, that trend gets even trendier — with dozens of creative, Seattle-styled sushi rolls, expensive Japanese-accented cocktails and 40-plus sakes sold by the bottle.

Step inside the slender, wood- and bamboo-enhanced entrance (the "front porch"), where pretty hostesses greet and seat. Here you'll find four large tables where happy-hour revelers revel in the fact that they can score cheap eats and drinks from 4 till 8 p.m., then again after 11.

That's some marketing tool: With those tables full up front, pleasure-seekers on the outside looking in are all the more willing to step through the threshold and move beyond it to check out the scenery in back. And what scenery!

The big room is divvied into various venues, each visible from the other, and each visibly different. The classic bar set-up fronts a partially open kitchen. Watch as bartenders muddle shiso leaves with Bacardi to create "lemongrass shisojitos" and garnish lime-stoked martinis with umeboshi — pickled Japanese plums ($10).

At the bar, as elsewhere, gracious servers offer complimentary edamame. While you nibble the salted soybeans, they'll help navigate a menu touting dozens of appetizers, most generously portioned, with prices averaging about $10.

These include a quintet of sea scallops, kicky with coarse black pepper and sauced with ponzu and yuzu. And bites of spicy ginger chicken — a light-handed take on General Tso's — that sings with ginger root.

Garlicky kalbi-style ribs are finger-licking good. And seafood gyoza, stuffed with shrimp and scallops, make this one of few places where those pan-seared dumplings are more than just an afterthought. Kasu-marinated black cod glazed with overly sweet miso, however, was too mushy. Ditto for the pound-cake-wrapped tempura ice cream.

Check out the daily fresh sheet for seasonal offerings like ruffles of chewy geoduck sashimi ($15), or a single sushi nigiri draped with buttery bluefin toro ($7). Then delve into the delightfully kooky list of specialty sushi rolls ($8-$15).

These are sliced into big colorful pinwheels invested with seafood that's cooked (tempura shrimp, broiled eel, snow crab) or not (raw tuna, scallops, salmon). That seafood is combined with herbs (shiso, cilantro), heat (jalapeños, chili aioli), fruit (mango, bananas, blueberries), dairy (mayo, cream cheese) and crunch (tobiko, tempura crisps, bell pepper).

Try the Banana Rama roll. I couldn't. The idea of barbecued eel with cucumber, avocados, bananas and blueberry sauce (what? no hot fudge?) was over the top, even for this adventurous eater. Instead, I got my eel- lover's fix via the Badboy roll, which pairs the eel with snow crab, avocado and cream cheese ($9, its price halved at happy hour).

My gotta-have-it roll? The Blondie: a honking oh-my-God-what-is-that? construction that is, essentially, a California roll given shock treatment. Wrapped with fine egg noodles, the roll is deep-fried till Blondie morphs into Medusa.

You'll do well ordering any of the standard rolls — spider, spicy tuna, etc. And sushi nigiri may be had singly, rather than in pairs. Worth noting: plenty of vegetarian sushi options, from shishito-pepper to enoki and chives.

For a "sake house," though, I found Umi's sake list unfortunately devoid of annotation. And I was disappointed with the breadth of the (too few) glass pours. The list isn't obviously grouped by provenance, price, flavor profile or degree of rice polish, leaving one to wonder about the difference between, say, a $30 "Nebuta Warrior honjozo" and a $140 Tentaka "silent stream" junmai daiginjo.

But that's where those delightful servers come in. Here to help — and to fetch another glass of medium-dry "Mu" (my sake of choice, served cold, in a wine glass, $11) — I sure had fun, fun, fun till the waitress took my Visa away.

Sample menu

Asari miso soup $3

Sashimi appetizer $10

Wild mushroom bake $7

Seared scallops with yuzu $12

Garlic short ribs $8

Blondie roll $9

Nancy Leson: 206-464-8838 or nleson@seattletimes.com. More columns at www.seattletimes.com/nancyleson.