Future song and linked eyes

Our first encounter was terrible. Our meeting is terrible each time. Our conversation is terrible each time.
You and me.
If we hadn't known each other, we wouldn't have changed.

However, we learned that:

It's more fun to be two of us.
The music can cross the line between a man and a non-human.
New sound appears from our encounter.
The more we know about each other, the tighter our bond becomes.

New "song" created by two binds us together and spreads to the world...