住吉 千里

Chisato is a second year female student at the Takafuji Academy and Yuuki's childhood friend. She is the president of Shokken, and also Mifuyu's  best friend. She does not like chocolate due to the death of her younger brother, who was fond of chocolate./

From url=http://en.wikipedia.org/wiki/Koi_to_Senkyo_to_Chocolate

She is Ayumu's cousin.