Chichibu [秩父] is a city in Saitama_prefecture. Chichibu is a beautiful town about one and a half hours from Tokyo. It is very famous for autumn leaves and the Chichibu Yomatsuri - a night festival that attracts thousands of people from around Japan.
The Seibu Chichibu Line (西武秩父線) from Ikebukuro is the quickest way to get to Chichibu from Tokyo. You can catch either a local train, which requires you to change trains at Hanno but is cheaper, or pay the extra surcharge for the speed and comfort of the Limited Express "Red Arrow" which is quicker and you dont have to change. Catch either of these from Seibu Ikebukuro station, which is accessible from the JR Line Ikebukuro station though the mall/walkway underneath the Tobu and Seibu department stores. If you have time, go though the food hall in the basement of the Seibu department store and grab something to eat on the train - local commuters will often eat their dinner or lunch on the train.