Oemgi , I' m so happy ! That's my first colab song! , That's song is ANTI The Holic , I use Koe with Akuko , I choose them because Koe voice some reason , like Rin , Akuko voice like Luka ~
Hnn , But i always thinking their voice like Ritsu Namine(Akuko) and Teto Kasane (Koe)
Ah! Anyways , here the link for download : http://soundcloud.com/usagihime-chan/utau-anti-the-holic-akuko
And , the author of Akuko , made the lineart and I colored that , That was Awesome !
She was made them sing at Youtube too ;)