[Tsuwabuki]

Yes. I had three tourist visas in a row (unusual, but possible) because I always showed "intent to leave." The first two were Korean ferry tickets, the third was an active job start date in Korea that immigration considered proof of "intent to leave" because who would have a job in Korea and no job in Japan and stay in Japan?

In fact, I burned both of my Korean ferry tickets (as in, did not use them) as I was waiting on my company in Japan to provide me with a Certificate of Eligibility so on my return to Korea I could get my Japanese visa. That's precisely what happened, but I never told that to immigration, and they never asked. The fact of the matter was, at that moment, I did indeed have residency in Korea and I did indeed have a job in Korea, even though I was quitting it.

If you show your Korean ferry ticket to immigration when you land from Canada, that will suffice for "intent to leave." When you come back from Korea, just show your Canadian ticket, and that will suffice for the second "intent to leave." Since you are a true tourist and not someone trying to jump through the visa hoops while in Japan, you should have an easier time of it, and I didn't have real difficulties.