A,A' Vol 1

From the VIZ Media edition

Science Fiction With a Romantic Twist. A, A' raises a troubling question: How would you feel if your lover died--and was replaced by a clone? Could recreate your relationship with someone who was physically exactly the same but didn't share any memories of your life together? In 4/4 (Quantre-Quarts), Mori, a teenager, is flunking out of an ESP training program. But when he meets Trill, a beautiful Unicorn, his latent abilities begin to blossom!...

Source: Anime News Network Encyclopedia