@Dominions SonCanadian law on the subject is complicated.
Currently the prohibition on under-18s being involved in pornography has been interpreted as also applying to fictional characters, including purely textual ones and cartoons. However, various police spokespersons have stated that they have no interest (or budget) in pursuing that interpretation on its own; rather, it is used as a legal pretext in combination with other factors.
For example, if someone reads the occasional story with a 15-year-old protagonist they are technically breaking the law, but aren't going to be charged. On the other hand, if someone has a profile on a suspected CP site, or is tracked downloading a bait file, or similar activities, then the presence of fictional underage porn activity can be used to file charges and get search warrants.
Just for reference, the Age of Consent in Canada is 16, with two close-in-age exceptions. Children 14 and 15 can have sex with someone who is less than 5 years older than them while children who are 12 or 13 can have sex with someone who is less than 2 years older than them.
There are also exceptions in the other direction. It's illegal for anyone in a position of authority (eg. teacher) or dependency (guardian) to have sex with anyone under 18. It's also illegal to have any form of "exploitative" relationship with anyone under 18. The last one is not strictly defined and is interpreted on a case-by-case basis looking at factors like how the relationship evolved.
tl;dr: The under-14 rules doesn't really fit with modern Canadian law, but it's not incompatible with common attitudes about sex outside the US. Kids are off limits, teens are experimenting but protected, adults are fair game.
Historical Note: The age of consent was increased to 16 from 14 in May 2008. The first story in the Swarm Cycle, Average Joes, was released in June 2007 and explicitly refers to fourteen as the new age of majority.