I am not trying to lie, evade or withheld information to custom officer on purpose.

I am Canadian from Vancouver, living in China as stated above.

X is China
Y is Japan
Z is Canada

So if i travel to Japan for sightseeing or for business I will answer truthfully my intend of visit. I mean I can go there for sightseeing or I can go there for business. So there is no intention to withheld any information or to do anything illegal.

With a Canadian passport living in China, every time I enter China they would ask what is the purpose of your trip, and I would answer I live and work here.

My fundamental question when ask the same question entering Canada is that are they asking why did I went to China because I am Canadian entering Canada? or why am I coming back to Canada? or both?

I hope this clear things up.