Sensei Greg Chow left Saturday for military duties in Iraq.

"His voice just stays in the room," said Greg's 11-year-old daughter Chrissy. "You can hear him over the crowd."

Added daughter Melinda, 9: "He enunciates his words, too."

Chow is an orthopedic surgeon in the Army reserves and will join a medical unit near Baghdad. He said he's had enough time to prepare mentally and logistically for the trip and that he'll miss the competition and his family that includes Tenri sensei and wife Robin and son Daniel.

"At least I've had the time to help them get prepared," Chow said. "I had the feeling up to this point that they're ready. Physically in terms of their training, we've done everything that we can and that we need."

The USJF Junior National Championships is expected to attract more than 1,000 judoka from the United States, Guam and Puerto Rico.

At last year's tournament in Boca Raton, Fla., 24 Hawai'i judoka won medals, half of which were gold. Tenri won 11 medals in Florida, including nine gold.

The event is open to judoka ages 7 to 19. Tomorrow's opening-round matches will feature younger competitors while the older ones compete Sunday.

With competitors having to go through as many as five or six rounds during the day, mental preparation will be a key factor toward winning.

"They need to be prepared mentally, to have the attitude that nothing is going to stop them, that they'll be able to persevere and keep on pushing and do what they have to do," Greg Chow said.

Daniel, 14, said that it won't matter if one has the technique and strength if "you don't believe that you can do anything."

Aside from the mental preparation, Chow said one needs techniques, physical strength and conditioning to make it through the tournament.

The tournament will also feature a variety of judo styles with judoka from different regions.

Judoka from Florida with a Cuban or South American background might have different leg picks, grips and dropping techniques not seen in Hawai'i while those from Chicago and the Northeast might have a European style that combines power and wrestling moves.

"Kids coming from the Mainland are physically stronger," Shobukan Judo Club sensei John Ko'omoa said. "The technique and conditioning is going to make the difference. How much they work on their technique is how well they'll perform."

With months of preparation behind them, Tenri's Whitney Elizaga said desire will carry anyone to the top.

"You're not going go out there to lose," said Elizaga, who recently graduated from Farrington. "You want to win because you didn't do all that training for nothing."

Here are some judoka from various clubs on O'ahu who are contenders in this weekend:

• Hodokan: Patrick Eglinton, Michael Fujiuchi and Tabitha Lum. All three took first at the state high school judo championships with Lum, who attends Maryknoll, successfully defending her title. Eglinton and Fujiuchi, who both attend McKinley, won for the first time.

• Kapolei: April Due, Bronson Peiper and Diane Mikuni. Due, of Kapolei High, won her 136-pound division at the state high school judo championship. Peiper, who was a part of Kapolei's first graduating class last month, has developed a variety of techniques according to sensei Leigh Nakamoto. Mikuni, 10, started in the novice division and gradually moved up in competitions.

• Leeward: Four sets of siblings are in contention for medals. They are the Campos sisters (Raena, Mika, Reiko), Zachary and Zoe Hernandez, Matthew and Jordan Ogata and Everett and Christian Pavo. Kara Takasaki, a state champion at Punahou, is also a contender.

• Salt Lake: Dane Pestano, Jordan Ng, Brady LaFortune, Justin Osumi, Reid Oshiro and Daron Maki. All five boys have won at least two medals at the junior nationals. Despite their age, sensei Daniel Fujikawa said the boys have become mature from the previous tournament experience.

• Shobukan: The club has more than a dozen contenders with several defending champions. Corey Jo Tashima, 16, will defend her title and could face teammate Catherine Chan in the Juvenile C 48-kilogram final. The two train together daily, which sensei John Ko'omoa said will help both of them out. "Practicing everyday with each other is like training with the best and by training with best, they will end up being the best," said Ko'omoa. Ten-year-old Kayla Mishima, competing in her third tournament, is also a defending national champion, who Ko'omoa described as "poised for a young judoka." Lianne Tomishima, 14, won a state championship at McKinley.

• Tenri: The club has about a dozen possible contenders. Along with the Chow siblings, there are Sharde Betances, Whitney Elizaga and Taylor Ibera. Ibera, 12, is making her sixth appearance at the tournament and will be looking to defend her title. Elizaga, 18, also a defending champion, is in the same division as Hodokan's Lum, an opponent she faced throughout the high school season. Betances, 17, competed for Farrington, which tied for the state team title.