However, I understand there are many Mami fans stranded since Ep.3 and they need something to cheer :) Besides, mahou shoujo has a tendency to produce promiscuous yuri pairs as doujin imagination really knows no bound. So I do not mind letting Mami fans having a bit of fun -- up till now we have Homu x Mado and Saya x Anko (nickname of Kyouko among fans in Japan) pairs and Mami really starts to look a bit lonely :)
OMAKE: The maths question in Ep.10 has answer in the Devil :