I *think* I remember the cels, correct me if I'm wrong:

At auction, signed by Watase Yuu:
*Aya
*Ceres
*Aki
*Touya
*Yuuhi

At Studio Pierrot panel, signed:
*Spoon's
*Aya close-up
*Aya pulled-back
*Touya

At Digital Manga panel:
*Aya

Keys