Kotonoha scares me too much for me to be ready to give her too much support.
Ha. She has her good points, though, so I'll keep her in mind when the main tournament starts. And Sekai... well... She's not a very likable character to me, from the very beginning.
Setsuna and Koko-chan, on the other hand... They had cute appearances in the OVA eps, safely outside the crushing badness that was the main series.
Setsuna was amusing as a mad scientist with a penchant for French, and Koko had the "take me oniichan!" cat girl getup.