"He is a natural," said Sensei Yoshihiro Okamoto. "He is like the student in math class who gets 100 percent on every test, plus the extra credit."
Karns studies at Okamoto's School of Karate, where he is a brown belt student who will test for a black belt in coming months.
Earlier this summer, he claimed his third consecutive world title in traditional weapons, using a bo -- a wooden staff -- and his second in traditional kata, or forms.
His forms win came performing the Wanshu Kata, which dates back to the 14th century.
Karns found martial arts on a doctor's advice after his parents sought help for their child's short attention span.
"His teacher said he was having a difficult time paying attention in class," said his father, Ken Karns. "That worried us, so we took him to a doctor."
The doctor said his patient was perfectly normal, but needed an outlet for his excess of energy.
He suggested martial arts, and Karns' parents found Okamoto's school.
Karns practices five days a week under Okamoto, who said he has the talent and ambition to compete at the black belt level.
"When he is competition, he is all business," said his father.
"The biggest honor for me will be when he looks back to me as a man and shares how much martial arts has helped shape his life and make him who he is," said Okamoto. "That will be worth more than any number of titles."
--The Anchorage Chronicle