* There's a typo. Double-check the spelling. Perhaps it's a similar phrase with slightly different characters.
* It's a regional dialect or slang. If you heard it from a specific group of people, it might have a meaning specific to them.
* It's a made-up phrase. It could be a joke, a nickname, or a creative invention.
To get a better understanding, please provide more context:
* Where did you hear this phrase?
* What was the situation?
* Who said it?
With more information, I can help you figure out what "ko toku waka" might mean.