In 1940, Otaka moved back to Japan where he took the role as conductor for the NHK Symphony Orchestra, become a music teacher and compose most of his significant works such as his Symphony and Cello Concerto, however his life came to an abrupt end at the age of 39, leaving an unfinished Flute Concerto rewrite which one of his students, Hikaru Hayashi, would take on and complete.

After the short stay, Otaka moved back to Japan to study composition with Klaus Pringsheim and piano with Leo Sirota.

[4] In 1937, Otaka won a Japanese-European music competition for his first Japanese Suite,[5] he was awarded by Felix Weingartner.

At some point after 1936, Otaka and his wife Misao (who also played the piano) met and became friends with Andrzej Panufnik,[9][10] who also came to Vienna to study conducting under Weingartner.

[14] Besides conducting, Otaka also composed prolifically, and had taught Hikaru Hayashi,[15] Kan Ishii,[16]: 22  and Kikuko Kanai.

[10] Due to his significant contributions to, and long stay with, the Japanese Symphony Orchestra, the Otaka Prize was created in his honour.

[27] When Hisatada Otaka died in 1951, the couple's children were still very young (Tadaaki being only 4 years old), and therefore Misao was left as a widowed mother.

[31] As such, Otaka's pieces result in a combination between eastern Japanese styles, and older tonal Germanic-Viennese style, even during his early studies in Vienna, Otaka showed Japanese traditional music, such as in his Japanische Suites, where Otaka made his pieces deliberately to "find new means of expression for the Japanese spirit... into the western tonal language", which was different compared to some of his peers who wrote only focusing on the European musicality.

30 is written in a specific French romantic style, although with distinct sections Japanese themes, it is written differently than many other concert works by Otaka, seemingly independent from the style of his teachers from Germany and Vienna, The Guardian said the piece had a "jazzy inflection" during the slower movement of the concerto, due to the French style and structure many French flautists performed the piece such as Jean-Pierre Rampal and Emmanuel Pahud[42] and was popular in France.