For the fun. For the challenge. For the power and control (you get to have just as many California rolls as you want). And, for many Hawai'i folk, for the nostalgic chance to recreate Mom's or Obaachan's home cooking.

Paul Onishi, who teaches sushi making to the public in noncredit classes at Kapi'olani Community College, said there once was a great gulf between the sushi bar and homestyle sushi, but that's changing a bit.

The sushi bar, which most Japanese could ill afford, was the home of high art, concentrated in the form of nigirizushi, the pressed rice cakes made from top-quality rice cooked to exacting standards and topped with top-quality raw seafood, grilled eel and other delicacies, he said.

The forms of sushi that became most popular in Hawai'i were the simpler ones — rolled, pan, cone and musubi — that in Japan would be made at home or in an okazuya (delicatessen) for takeout or picnic-style dining.

Even if these were made in a sushi bar, their taste and texture would be different, because of the more exacting techniques used, he said. For example, chirashi ("scattered") sushi in a sushi bar would be made with costly seafood strewn artfully over the top, while at home vegetables and eggs would be mixed right into the rice.

"The sushi bar was the sushi bar and the ordinary people never got to taste that particular texture, that style of flavoring," Onishi said. Now, however, many more people can afford sushi bars, both in Japan and here.

More experienced palates and generous pocketbooks mean we may make our home sushi with higher-end ingredients than Grandma did — smoked salmon, avocado mayonnaise, caviar, top-quality 'ahi, Kahuku prawns. But it remains that we must learn the proper techniques in order to make sushi.

Here and on the Mainland, sushi-making courses are ever more widely available. Enrollment is high at the California Sushi Academy in Venice Beach, Calif., where twice-weekly daylong classes are taught, along with shorter-term demonstrations and a new sashimi program for those ready to go on to the art of choosing and cutting fish, said school director Danielle Chase. The school teaches both traditional styles and Western variations on the theme (using tortillas instead of nori, for example).

Onishi's course at KCC is the longest-running noncredit class there, offered for the past 16 years. "Sushi always has that draw," he said. "At the same time, especially when I started teaching, many people in Hawai'i had never set foot in a traditional sushi bar."

Hawai'i-born Onishi recalls his training in Los Angeles at the hands of Japanese sushi masters who were so strict that each rice cake (to be topped with a piece of sashimi) had to conform to a numeric standard: 250 grains of rice, plus or minus five grains.

Onishi noticed right away that the techniques, the tastes and even the rice used were different than those used by his mom and grandmother back in Hawai'i. But he grew to deeply appreciate the skill and training required to create sushi in the formal and traditional style. When he returned to the Islands, he began teaching courses designed to help locals understand not so much sushi technique as sushi culture.

Sushi-bar sushi, he said, is all about rice: learning to make and shape rice properly is the culmination of a decade of training. He recalls watching the ladies at Japanese festivals in Hawai'i turn huge, steaming pots of rice out onto tables covered with brown paper, skillfully flavoring and then rolling the rice while it was still warm. The results were so 'ono to us, but to master sushi makers, the whole process would be wrong.

Rigid rules govern the preparation: Use top-quality rice, wash it well but in a minimum of water, pour scalding hot water over the rice just before you cook it, then steam it in slightly less water than is usually called for. Once the rice is done, let it sit without removing the lid for 10 minutes. Then immediately turn it into a wide, flat utensil and begin folding in the sushi-zu vinegar-sugar mixture while fanning vigorously with the other hand. The result should be rice that glistens, that has a slightly al dente bite and no broken grains, and that is neither too sticky nor dripping with vinegary sauce. The rice must be allowed to cool before it's rolled or shaped, Onishi said.

Mainlanders who attempt sushi sometimes have to start by conquering their wariness of making rice, not a problem for Islanders, most of whom have mastered the art of throwing equal parts of rice and water into a rice cooker.

But sushi rice is another matter: The vinegar-mirin-salt-sugar mixture that flavors the rice must have the correct balance of sour to sweet.

Then there's the problem of shaping the rice, which tends to cling to your hands. The standard solution, wetting your palms with water, has its own problems.

At a recent sushi-making class at Sai Cafe in Chicago, chef James Bee spent time on this procedure. "Spreading the rice is difficult. If you don't use enough water, the rice sticks to your hands. Push down too hard and it breaks. Put too much water on your hands and it drowns," he said.

Bee showed the class how to dab just enough water over the palms to give them a gloss. "The key point is to make it over and over," Bee told the students who were patting the sticky rice into rectangles during a recent class.

Bee said sushi makers have success only if they use proper sushi rice.

"Rice is different every growing season," Bee says. "In this country people say, 'I don't care about the rice as long as you give me good fish.' In Japan, they care."

In Hawai'i, California-grown brands of rice for sushi are readily available in most supermarkets; Japanese rice is sold at Daiei, Marukai and other Asian stores.

It is customary in Japan to test the quality of a sushi bar by first ordering tamago sushi — sushi made with a delicate egg omelet that doesn't mask the flavor of the rice. If the rice doesn't stand up to scrutiny, the sushi connoisseur may move on.