Okai Chisato (岡井千聖) born June 21, 1994 in Saitama, Japan. She joined the Hello! Project Kids in year 2002 and currently a member of ℃-ute. She was in a Hello! Project unit called Athena & Robikerottsu together with Niigaki Risa, Mitsui Aika, and Nakajima Saki. Her younger sister, Okai Asuna (岡井明日菜), was a member of Hello! Project Egg. Read more on Last.fm