Shichiyō Kōgaku Kōgyō K.K. (七洋光学工業㈱) was a Japanese camera maker in the mid-1950s. It made the Pluto Six 6×6 folders and the Stereo Pluto 35mm stereo camera in 1955. They were distributed by K.K. Pluto Shōkai (㈱プラトー商会), which was certainly an associated company. The address was given at the time for both companies as Minato-ku Shiba-Mita 2–11 (港区芝三田2–11) in Tokyo. These models did not meet a great success, and all trace is lost after that date.
- 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.