Volume 1:
Riya Narukawa is a high school freshman with a tremendous talent for the violin, and an equally large bag of mental issues. He seems to have a split personality. After injuring his own hand to compromise his playing ability, he winds up on the doorstep of college student Atsushi Ikeda. Atsushi's a nice guy, maybe too nice and generous. He takes Riya in for the night and helps him with his hand injury. Atsushi realizes there is much more Riya than is on the surface, and learns just how difficult Riya's life actually is. Not only does he have a personality disorder, but there's an aggressive senior at his school who has his eye on him. Atsushi becomes a sort of safe haven for Riya, an escape from the life of music he's been bound to.

Volume 2:
In Volume 2, the crescendo builds as "Black" Riya becomes more dominant and, if he has his way, would erase "White" Riya from existence. But whichever personality surfaces, kind and compassionate Atsushi is ready to burst into a torch song for Riya, after realizing that he is in love with the confused young man. Upperclassman Kousaka, however, is set in derailing the symphony that is Atsushi's and Riya's relationship. Kousaka, you see, has feelings for Riya as well. Will the concert end with a standing ovation or is Il Gatto Sul G. a one hit wonder?

Volume 3:
In this final volume of the Il Gatto saga, things come to a head when White Riya becomes aware of his other personality, while the otherwise self-assured Black Riya is fast becoming lost in the confusion. Meanwhile, White is being drawn to spend the night with his violent sempai Kousaka. But on the other hand, Black is trying to seduce the gentle and protective Atsushi. Only one Riya will be left standing in the end. But who will it be? Black or White?

Official English Release: June

Notes:
-Adapted to Drama CD.