He learned directly from Masutatsu Oyama .
Was a senior instructor in Masutatsu Oyama 's International Karate Organization ( IKO ) until 1991 , when he resigned from the IKO .
He learned directly from Masutatsu Oyama and was a senior instructor in Oyama 's International Karate Organization ( IKO ) until 1991 , when he resigned from the IKO .