AS~Angelic Serenade

You are a teenage boy traveling to find the angel that stopped you from aging. You don't remember it very well since it was what, ten years, twenty years ago? Maybe even longer. Other than the clothes on your back, you carry a magical, musical instrument and the feather of the angel you are searching for. One day, you come across a girl. This girl is very different. She can't talk and has different colored eyes. Her left eye is dark blue and her right eye is fire red. This is how the game begins.

[From GameFAQs]