This made me giggle uncontrollably.Is that different from Japanese?
Where the heck ever he is from Kang is NOT pronounced Gung.Different war, 3R.
That's a LOT closer than a K becoming a G and an a becoming a u.You are using English as your frame of reference and trying to fit a sound into the 26 letters you know.
The short answer is it has to do with how they converted their sounds/written script to English. For whatever reason that sound was made into the letter K for writing purposes.
Why is Ichiro not Eecheeroh? Same reason.