Heart Sangyō K.K. (ハート産業㈱, Hāto Sangyō K.K.) was a Japanese camera maker in the mid-1950s. It was mentioned as the maker of the Stereo Leader in a 1956 advertisement; previous advertisements for the same model were listing the maker as Tōgōdō Sangyō. It is not known if the production of the camera was transferred to Heart Sangyō, or if this was a sub-contractor of Tougodo from the start. The address in 1956 was Meguro-ku Mita 54 (目黒区三田54).
- Asahi Camera (アサヒカメラ) editorial staff. Shōwa 10–40nen kōkoku ni miru kokusan kamera no rekishi (昭和10–40年広告にみる国産カメラの歴史, Japanese camera history as seen in advertisements, 1935–1965). Tokyo: Asahi Shinbunsha, 1994. ISBN 4-02-330312-7.