There is no way Konata can be this cute!! At least for me, Konata never displays any form of feminine behavior that would remind you that she is actually a girl unless she cosplays which isn’t the real her. That is, until Tsumiki shows me how it can be done properly. Not only that, Tsumiki isn’t your typical tsundere which is a plus in my book. She only acts tsun to Mayoi but dere to Io which is not a typical way of how a tsundere behaves. Her moe level is extremely high as well. There are not many anime females that I can compare her with in terms of genuine moe but the most recent one I can recall is Towa Erio from Denpa Onna.
Io is also not what you would expect from a typical anime male protagonist. The guy is awesome. I usually dislike it when guys were added into the main cast in this kind of anime. Most male leads in anime are obnoxious; creating an unpleasant atmosphere to the series. Female casts often label them as perverts or idiots, but Io is nothing like those guys. He is kind, gentle, and able to remain composed in most situations. I don’t really mind his presence at all and rather ok with the idea of him going out with Tsumiki. They’re perfect for each other as master/pet couple if that term even exist.
Now moving on to the supporting casts, Mayoi is quite fun and possible trickster character but one can’t help but wonder what’s hidden behind her bang. Maybe there is more to it than just her eyes, that is, if she even has eyes at all.
And there is Hime, so she gets nosebleed every time she imagines Tsumiki being cute?
I don't think she's into yuri either.
Lastly Sakaki, I have nothing to say about him yet until he gets more spotlight latter. For now he is just Io’s only male friend and a bit of a pervert.