CanCam (キャンキャン) is a fashion magazine for women in their late teens and early 20s. AneCan (姉キャン, although that 姉 really should be in a circle) is the "older sister" (ane) version. Now, I know what you're thinking: if both end in キャン, why does one spell it Cam and the other Can? Let me explain.

The name CanCam comes from the English words "can" (be capable of) and "campus" (spelt キャンパス, in Japanese, because ン becomes a bilabial nasal before パ). The magazine's assumed reader is a woman attending university, and its implicit promise is that if she follows its advice, she will be judged fashionable by her fellow students and become wildly popular as a direct result. A happy and fulfilling campus life will follow. In other words, she who reads CanCam "can campus". (See comments -- thanks Marxy)

So the final <m> in CanCam is not some wild romanization scheme to represent the utterance-final realization of /n/. (Uh... not that anyone would assume that.) It's just used because that part of the word happens to be short for "campus".

But the second half of AneCan is short for CanCam, not "campus", and so by the same rules (take the first part of the word) an <n> is indicated. This also allows AneCan to subtly excise the "campus" part of its identity -- its target readership has graduated -- while still retaining the CanCam part, one semiotic level above. Diabolical. Beautiful.