A great and jam-packed episode. Yamada actually wearing her glasses, Ichikawa's sister being a true sibling and waiting until they're trapped in the car to pester him, and Moe looking like she's going to slot herself into the wingwoman role are my highlights.
It's nice to have the power/magic system explained, though it seems a bit... Vanilla. I also thought it was a nice touch that though Mai magically grew, she didn't suddenly go from mute to an eloquent speaker.