TDK Corporation (TDK株式会社, TDK Kabushiki-gaisha) is a Japanese multinational electronics company that manufactures electronic materials, electronic components, and recording and data-storage media. "TDK" is an initialism of the original Japanese name of the company: Tokyo Denki Kagaku Kōgyō K.K. (Tokyo Electric Chemical Industry Co., Ltd.). The company is listed on the Tokyo Stock Exchange and is a constituent of the Nikkei 225 and TOPIX indices.