東映動画の起源は、戦前に活躍したアニメーション作家、政岡憲三と山本早苗が創設した日本動画に遡る。敗戦直後の世相を反映した「トラちゃん」シリーズ等を発表したのちに日動映画へと改称し、東映教育映画部の委託によるアニメーション制作を開始した。最初の委託作品は、薮下泰司（藪下泰次）演出による『うかれバイオリン』。本作の好評を受けて東映は日動映画の買収を決定、これが東映動画の発足へとつながった。なお、薮下は文部省教育映画課の嘱託として文化・記録映画の撮影や演出に携わった経験を持ち、演出として東映動画の中枢を担っていく。
The origins of Toei Animation trace back to Nihon Dōga, founded by pre-war animation artists Masaoka Kenzo and Yamamoto Sanae. After releasing the "Tora-chan" series, which reflected the social conditions immediately following Japan's defeat in the war, the studio was renamed Nichidō Eiga and began producing animations commissioned by the Toei Education Film Division. The first commissioned work was "Ukare Violin," directed by Yabushita Taiji (also known as Yabushita Taiji). The positive reception of this work led Toei to decide on acquiring Nichidō Eiga, which in turn led to the establishment of Toei Dōga. Notably, Yabushita had experience shooting and directing cultural and documentary films as a commissioned staff member of the Ministry of Education's Film Section, and he would go on to play a central role as a director at Toei Dōga.
Source: cinematokyo.com · Tokyo mini-theater & independent cinema showtimes.