Hidamari no Pinyu

From the Animeraider: One morning Minato misses her bus to school after running into a pretty girl who seems lost and can barely speak Japanese. Later she runs into her in the street and she's filthy, but she's carrying a locket with a picture of Minato's grandfather in it, and this strange girl knows Minato's real name of Minuette. She calls herself Pinuette and is looking for her... Son-in-law??! Just who is this girl?