@Zeria I'm thinking the artist is using the characters image colors thus Mari would make more sense than Yoshiko here. Kanan's color is green, You's is blue (cyan), Chika's is orange, while Yoshiko's color is grey and Mari's is purple. So unless the artist made a mistake, it is Mari and not Yoshiko.
Are there really people who do not like it?? That's weird. I'd thought people would be glad we got a canon couple...
I think Chika x Riko is a great pairing!
I guess other people (and myself) just like childhood friend romance (Chika x You) more than this ship. That and the ship seemed to be pushed a bit too much in the anime for people's taste.
This ship seems to have a similar feeling to that of Hanayo x Rin in that they have similar personality dynamic going on. Hanamaru (Rin) is the outgoing energetic one, while Ruby (Hanayo) is the shy one. Not sure that's a good or bad thing though.