Like the rest of the original characters, hopefully we won't see them anymore in the comics.

Amusingly, Ryo has turned up in three other comics -- strip 850 (post #2625994), strip 1264 (post #3459472), and an as-yet untranslated strip (so I don't know the number), post #3546790 . The other girls (plus Yumeko) are in the second, too, and Ai recurs in the third (though it's pretty much a cameo for them both).