Ii am a bit surprised by your comment about price. I fly AC a lot and always book on their website and usually the price of the return ticket is just the sum of 2 one-way tickets.
You can book a one way ticket directly on Air Canada's website; it's less than buying a return. You'll also be able to choose your own seat this way. No need for a travel agent
While these comments can be correct, they do not neccessarily apply to someone living in Japan to somoene buying an Air Canada ticket in Japan. And yes, one way fares Japan to Canada can cost more than return tickets.
Similary for Canada-Europe. Mid October AC wants one way price of $5,020 for Toronto-Zurich as their cheapest one way fare one way they sell for that is a Latitude ticket. A return ticket Mid october ticket (Tango) costs $968.17.
So, think about it ..one way over 5,000. Return, under 1,000.
No wonder people throw away the return portion sometimes.
Edited: 1:04 pm, September 24, 2013