Plot Summary: source - animenewsnetworkDOTcom
Yuichi Aizawa returns to this city after seven years. In his childhood, he often visited it, but something happend in the past which caused him to block out his memories of the events of seven years ago. On the day after he gets settled in, he meets a girl carrying a backpack with wings on it. Her name is Tsukimiya Ayu and he begins to recall the memories he had lost.