Tokai guitars can be brilliant, you might have a hidden gem on your hands. Chuck it this way if you get fed up.
It’s probably the way the string is mounted on the tuner that’s causing the problem, so invest in a new set of strings, check the right way of fitting them for your tuners and give it another shot.
Jimification has a good point. If you’ve got a different gauge string than was on it before it might not be sitting in the grooves just right. Sometimes a bit of light sanding/filing can help followed by the application of graphite lube (rubbing with a pencil lead).
Oh, and on an electric the G string is usually plain, not wound. Unlike an acoustic. Check you’ve got the right type and gauge.