This is your K. hornbeam...is it in a lot of sunlight? I keep mine in mostly shade this time of year. When do you water, any chance it's late at night when you get home and it sits wet all night? How about a better shot of the base, does it have some dark mildew creeping up the section of trunk that's most-shaded?
Yours is possibly from the same batch of Bonsai West's import KH as mine.
Thanks guys hey Dave do all the leaves fall off what happens thanks for the replys