I regularly train in the Bujinkan and my instructor, like many who has been in the Bujinkan for a while has trained in a few other martial arts over the years. He sometimes shows us snippets of techniques from other martial arts as well as Bujinkan style counters to them (or just what to watch out for) and is a proponent of cross-training and trying out other styles to learn different things and perspectives that can complement our training. I have trained in a few other styles and with other people (only really Japanese martial arts, some other Bujinkan classes) and recently thought I would go and try out something else. I went to try a Fujian White Crane Kung Fu school and was told by the instructor that he doesn't teach anyone who trains in any other martial art because he couldn't teach people when he doesn't know "what they've been taught and why they've been taught it" and that you "can't have two masters". I found this response very bizarre. I'm not trying to bad-mouth any particular school or style here, but I found it at odds with the inclusive and welcoming attitude I've found at most martial arts classes. I don't understand why he thinks he couldn't teach me his own style just because I learn something else. I also play squash and badminton and I can't imagine a coach telling me "I can't possibly teach you badminton if you also play squash". Does anyone have any insight or comments into this as an instructor? Is this something specific to Chinese martial arts or White Crane Kung Fu? I've never had an issue like this before and most people I've met from other styles seem quite interested, even asking how we do things differently technique-wise in the Bujinkan.