Kanon

Kanon () is a Japanese adult visual novel developed by Key. It was released on 4 June 1999. It is playable on Windows PCs. Key later released versions of "Kanon" without the erotic content, and the game was ported to the Dreamcast, PlayStation 2 and PlayStation Portable. After the game's release, Kanon made several transitions into other media. Two Manga series were serialized in Dengeki Daioh and Dragon Age Pure. Comic anthologies, light novels and art books were also published, as were audio dramas and several music albums. Toei Animation produced a 13-episode anime television series in 2002 and an original video animation (OVA) episode in 2003. Kyoto Animation produced a 24-episode anime series in 2006.
The story follows the life of Yuichi Aizawa, a high school student who returns to a city he last visited seven years ago, and he has little recollection (memories) of the events from back then. He meets several girls and slowly regains his lost memories.
Characters.
He is the main character of the story. He is friendly and outgoing. In the beginning of the story he moves to a new city and lives with his cousin, Nayuki Minase. He visited the town many years ago, but has since lost most of his memories of the place.
Ayu is the main female character of the story. She is lively and energetic, and wears a backpack with wings on it. Her catchphrase is "uguu", which she uses to express emotions such as frustration, anger, or fear, Yuichi enjoys teasing her about it. She refers to herself as "boku", a Japanese masculine word for "I". Her favorite food is taiyaki. Although she looks very young, she is actually the same age as Yuichi (17 years old).
Nayuki is Yuichi's cousin. Yuichi moves in with her at the start of the story.
Mai is a third-year student at the same high school Yuichi goes to. He met her standing alone in the school building at night, with a sword in her hand. At nighttime when no one is in the school, she comes in to fight and defeat demons. People are always blaming her for accidents that happen at the school, though she never denies them.