Well everything we've seen up till this episode had portrayed her as being pretty cold, but the newly revealed encounter when Junichi got dumped showed how she's actually pretty upbeat and caring inside (towards her brother, at least). There wasn't a real need to mention her brother when the shopping conversation came up, but she did leave him out.
So far she resembles Haruka the most. They're both into teasing Junichi, though Ai is much more realistic and understandable in this regard. She just enjoys joking with people and seeing them flustered while Haruka's randomness was all over the place. Both of them also see him as "cute" whereas Sae and Kaoru saw him as a more reliable person.
It's great how the past girls continue to be fun. I chuckled at "embarrassing clothes" - it didn't occur to me that Sae made the black dress herself.
Also loved her cream pancake metaphor.
Fetish count: swimsuit, pansu, upskirt.