Perhaps it is writ deep into the psyche of our native land, but Americans are unaccustomed to gastronomic rules. Proper etiquette is dictated by the all-powerful edicts of Miss Manners: the ubiquitous "no elbows on the table," the less common, unwieldy knife switch-over between cutting and chewing and the taboo against soup-slurping. But etiquette in American dining is about propriety and little more. According to the owner and chef of Cafe Japonaise, things are different in Japan. Sushi neophytes need more than a willingness to embrace the strangeness of raw fish. Eating sushi is a matter of taste and technique.

Many Americans simply fail to appreciate sushi because they do not know how to eat it. I have grappled with the debate between one large, indelicate bite versus the risky maneuver of massacring the piece of fish in the attempt to sever it. My sinuses have been singed clear as a bell by accidental over-indulgence in wasabi. I have even been so gauche as to try to remove the seaweed from one roll so as to taste it plain. However, the art of properly eating sushi extends far beyond overcoming these trifling blunders. For instance, as our chef explained, most people attempt to differentiate good from bad sushi by the quality of the fish, a distinction that can be misleading because most well-reputed Boston sushi houses are serviced by the same supplier.

The key to good sushi lies in the oft-overlooked rice, which has to strike the right balance between vinegar and salt. Straying too far toward one or the other extreme is treacherous and detracts from the flavor of the fish. Additionally, the consistency of the rice is imperative. Once the proper proportion of ingredients is calibrated, the rice is compacted on mats into little rolls. In the absence of adequate air between the grains, the texture and flavor are ruined. When the balls of rice supporting nigiri sushi are too compact, they interfere with the customer's experience of the fish. To further complicate matters, even if the fish, rice and presentation are perfect, everything can be mucked up with a simple flick of the wrist. The bane of all self-respecting sushi-makers is the over-zealous American, raised on Tabasco and A-1, who saturates the humble roll with soy sauce. There are no two ways to dip; in the case of nigiri it is always fish-side down.

The resident chef of Cafe Japonaise has a point. A soy bath drowns out the nutty taste of more delicate fish like suzuki (sea bass) or yellowtail. Crab sticks ($3) are supported by thin strips of cucumber and held together by a ribbon of seaweed on top of a gently formed and richly textured ball of rice. Velvety tuna is pounded into the texture of tartar and mixed with scallions in the Tuna and Scallion Roll ($4.50). Iridescent slabs of yellowtail arrive on a platter ($16.50) with translucent pink tuna slices, striated salmon, and a seaweed purse brimming with giant red roe. A fat pink shrimp is split open to straddle a ball of rice, and a rather suspicious-looking orange mush in a seaweed packet turns out to be sea urchin. Mixed rolls were similarly elegant: Boston maki ($4.50) arrived in neat rolls filled with salmon, avocado and lettuce, Spicy Tuna ($5) walked a perfect tightrope between cucumber, tuna and subtly tangy spicy sauce. Cafe Japonaise has a chef who has turned sushi-making into a science and one can understand why he wants his clientele to get as much out of it as possible. It is obviously a sushi restaurant that wishes to transcend the fluorescent-lit clatter and bustle of its Boston counterparts.

The very look of the place is atypical: gone are the origami sculptures and cafeteria-like counters; waitresses in kimonos are nowhere to be found. Instead, Ella Fitzgerald croons from the stereo and marbled black tables are lit by suspended pearlate lamps. A richly-patterned curtain is elegantly draped to frame the window and an enormous fish tank full of exotic fish is sunk into the wall above the sushi bar.

The desolate location on Commonwealth Ave. has obviously taken its toll on the restaurant, however. It is nearly empty (admittedly Sunday nights are never the most bustling) and the lights are turned up just a tad too bright. In fact, Cafe Japonaise just re-opened two weeks before our visit, offering only its delectable sushi rather than the full Japanese menu that was available prior to its closing. The restaurant's chef is on a mission to create an entirely new menu, however, which will include both sushi and a more international, French-Japanese fusion cuisine fit for the new millennium. She plans to move to a location that serves more than the occasional walk-in or rowdy B.U. student and translate her upscale sushi into a more upscale total dining experience. For the time being, one hopes the prices will remain unsullied by her upscale impulse. The kitchen serves only sushi, but the portions are generous, the quality impressive and the prices relatively low. On top of it all, the maitre d' answers every question with an almost exultatory "Yes!" Yes, indeed.