The Marché Clandestin MANGAYA is conveniently located just above the Marché Clandestin: 325 Ontario Est, Suite 101, Montreal, Qc, H2X 1H7 (Ph: (514) 510-6507; Web: www.mcanime.com/mangaya/). It is open Monday to Saturday, from noon to 7 pm. It is near the Berri-UQAM métro station.
As far as I know it is the first store in Montreal to specialize only in manga -- both in French and in English (and eventually in Japanese too!). It covers all genres: shojo, shonen, yaoi, yuri, seinen, etc., and even carries novels. They have a special: buy 10 manga and get one free (of a value up to $12.95 Can).
It has just opened so the place is small and they don't have a large selection yet, but they already have a nice choice of manga and many titles that you would never see in your regular book store. It is REALLY worth checking out.