The company began to research pistol-shaped cameras in 1949, with some degree of official support, certainly from the Japanese police forces. The first model was the Doryu 1, taking 9.5mm film, completed in 1952. It was never produced and the development team switched to the Doryu 2-16 on the same year, taking 16mm film. The new model was completed in July 1954, but was not retained by the police forces, who preferred the competing Mamiya Pistol. The camera was released to the general public instead, even if it was not meeting any obvious need. In 1955, the company advertised the camera from an address in Tokyo, Shinagawa. It seems that late advertisements were placed by the company Nihon 16-miri Shashin Kōgyō K.K. (日本16粍写真工業㈱, meaning Japanese 16mm Photo Industries), certainly a successor to Doryu Camera.
- The English name "Doryu Camera Company Ltd." is confirmed by the user manual of the Doryu 2-16 pictured in Pritchard, p.147.
- Andō, p.214: 昭和24年関係当局の応援を得て[...]設計しました[...].
- Andō, p.214: 昭和27年に完成したドリウ1-9.5型.
- Andō, p.214: このカメラは[...]発売に至らず、同年新たにドリウ2-16型を設計[...]しました.
- Andō, p.214: 昭和29年7月完成しました.
- Nakajima, p.144 of Kurashikku Kamera Senka no.35.
- The address was Tōkyō-to Shinagawa-ku Ōikurata-chō 3355-banchi (東京都品川区大井倉田町3355番地). Source: advertisements dated July and September 1955 reproduced in Kokusan kamera no rekishi, p.153.
- Kokusan kamera no rekishi, p.356.
- Andō Katsuyasu (安藤勝康). "Doriu 2–16 gata kamera" (ドリウ2–16型カメラ, Doryu 2-16 camera). In Shashin Kōgyō no.33 (March 1955). Pp.214–7.
- 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.
- Nakajima Akitoshi (中島章年). "Kenjū magai no yunīku na sutairu — Doryū 2-16" (拳銃まがいのユニークなスタイル・ドリュー2-16, The Doryu 2-16, with a unique pistol-like style). Kamera Rebyū: Kurashikku Kamera Senka (カメラレビュー クラシックカメラ専科) / Camera Review: All about Historical Cameras no.35, November 1995. Nihon no kamera 50nen (日本のカメラ50年, special issue on 50 years of Japanese cameras). P.144.
- Pritchard, Michael and St. Denny, Douglas. Spy Cameras — A century of detective and subminiature cameras. London: Classic Collection Publications, 1993. ISBN 1-874485-00-3. Pp.146–7.