according to wikipedia Japan, the many manifestations of`comme ca` appear from one of the largest apparel makers in japan called five foxes which is also a company famous for not having a company website (which is probably why the OP had such a hard time finding information)
theres COMME CA ISM: a store for daily goods... utensils, interior decorations, littleknickknacks and super cheap clothes
COMME CA DU MODE: another fairly reasonable priced store which is something like GAP or sometimes like an OLD NAVY or uniqlo or such. they focus on being able to give customers options on `total coordination` (or buying whole ensembles in one shot) and less on design.
COMME CA COLLECTION: designed by Kenji Ito. Is shown at Tokyo collection... far more design-based, there is even a shop ampng all the other high^brand boutiques in south-aoyama.
I actually like some of the collection stuff, but the only things I have bought from du mode or ism are little cheap travel suitcases or makeup bags etc...