Use of the term Aikido"ka"
When I started Aikido, I would often hear the term Aikidoka to reference someone who studied Aikido. I just thought this was a normal thing to do. Then at some point I learned that adding "ka" to the end was something that should only be used when someone was very accomplished at something. That is to say you wouldn't add "ka" unless the person what quite adept at the art. I also learned that you should never reference yourself and an "Aikidoka" because that's being boastful, and only others who really respect your ability should refer to you that way.
Here in California, I know that no one minds you calling yourself an Aikidoka. And we call other people who do Aikido, even if they are not yudansha, Aikidoka. Would this seem very strange to your average Japanese person?