Tori no Uta (OVA)

On his way home, a boy encounters a mysterious girl in a crimson kimono with a green bird on her shoulder. She captivates him, then vanishes, leaving a green feather bound to the promise that they will meet again.

He returns to his hometown 50 years later, having let that encounter slip from memory. The girl and the bird draw him back toward a past in which dreams, longing, and reality can no longer be cleanly separated.