Hikaru Sakuraba is the biology teacher at Ryōō High School, and is the homeroom teacher of Kagami's class 3-C. She is also the captain of the Lucky Star informational ad section, which was renamed "Lucky Paradise". She is feared by Akira, but Akira later calls Hikaru a betrayer. She likes CalorieMate and sleeping, dislikes vegetables, and people who quickly misunderstand things. She is Fuyuki's good friend, who works as a school nurse. She appears briefly in episode twenty-four of the anime, making sure that Akira and Minoru will do things right, who are in bad terms after the event of episode twenty-one of "Lucky Channel".
http://en.wikipedia.org/wiki/List_of_Lucky_Star_characters