Kanon
Kanon is a Japanese visual novel developed by Key that tells the life of Yuichi Aizawa. The high school student returns to a town he last visited seven years earlier and can barely remember the events of that time. He meets several girls and slowly regains his lost memories.
Story
Yuuichi Aizawa, a high school student, returns to a town he last visited 7 years ago to live with his aunt and cousin. For a reason he doesn't exactly know, he can barely remember his last visit, but that doesn't seem to bother him too much at first. The day after he arrives, he goes into town, where he bumps into (literally) a girl named Ayu Tsukimiya, and Yuuichi's memories slowly return.