The purpose of this paper is to analyze Toei Doga (established in 1956 and renamed to Toei-Animation, Inc.) from a movie historical view point. This paper consists of 12 chapters including introduction, main 10 chapters, and conclusion. In the introduction, I indicated the establishment data of Toei Doga, described a relationship between Toei Doga and Nichido Production and raised its induced problems. In the following main chapter, I mentioned a role of Toei, a parent company of Toei Doga and established five years earlier than Toei Doga, in Japanese movie scene after the World War II. Then, I discuss about a leading role of Toyoko Eiga, the antecedent of Toei, in Japanese movie history. Specifically I focus on the fact that the other film companies did not have a development section but only Toyoko Eiga had. The development section in Toyoko Eiga first mainly worked for traveling film shows and later produced, distributed, and performed educational 16 mm films, which included some short animation films. These short animations burgeoned into Toei Doga und er the leadership of Okawa, the president of Toei. I demonstrated this process with showing data. In fact, the establishment of Toyoko Eiga is based on Negishi1s reorganization plan about the restructure of film industry after the World War II. Negishi has had his wish to establish a film company to give staffs of the former Man-Ei a new job in the film industry. This implies that the producing system of the former Man-Ei was transferred to Toei Doga through Toyoko Eiga and Toei. It is very important for historians to use raw materials to demonstrate their historical descriptions. However, I have missed some important records to verify my historical description and may misread the record and data I used here. Therefore, I hope that this paper be read as a tentative hypothesis that stimulate researchers to make a further study.