Sumiko Kobayashi, is the Junior Detective League's class teacher. Actually a kind person, in her initial period at Titan Elementary she was known as "the witch" due to her harsh behaviour to her students, which was in fact prompted by a previous bad experience and her innate stage fright. With the help of Conan and his little friends she has warmed considerably, and after having seen the Detective Boys in action she has even appointed herself as their manager. When she wears contacts, she looks like officer Sato.
(Source: Wikipedia)