Maybe SInger/Actor Ching Saan is wrongly billed (I failed to locate him) But maybe this is another missing mayor role actor who seems to be a real life senior Judo expert (probably a Japanese) who is even in the credits seuqence shown as teacher (Sifu) of Lily ho and the Judo class ... Could it be a synonym for a Japanese Name?
Added costumes, assist. dir. and art dir. Ching Saan plays "Okawa". If the name of the judo teacher is "Okawa" you will know what you should do. Ching Saan (??) in Japanese is "Aoyama".