I just recently watched the Two Akane's OAV, and I noticed some
interesting things.. 

The animation is 'different' -- most of the characters are 
drawn differently, almost like they are in AMG and 
You're Under arrest.  This is most prominent when you see
someone from the side -- the contour of their face, and the
off-center round mouth is just like Natsumi and Miyuki from
YUA..

The other thing was, ukyou didn't look like Ukyou at all! 
I wouldn't have recognized her w/o the voice.