Nine Star Ki (Japanese version of Flying Star Feng Shui)
Basically 9 Star Ki Feng Shui is one and the same as Flying Star Feng Shui.
The difference is that Flying Star Feng Shui is more specific and focused on e.g. evaluation the birth chart of the house.
9 Star Ki Feng Shui actually uses the same 9 grids of the Luo Shu Grid. But the difference is that; in my opinion, it was exported to Japan. And it is equally popular in Japan and United Kingdom.
One should understand the Japanese culture. The Japanese culture, in respect of Feng Shui wants to use it more in totality or as a package.
Thus 9 Star Ki, looks at not only evaluation of the house but it also combines the personal readings.
In my opinion, it is difficult to mix and match 9 Star Ki and applied it together with Flying Star.
I feel that one should either use 9 Star Ki or Flying Star as some how, if one mix and match.. it usually does not come out `right' or you often get the `wrong' answers halfway using half of each method.