Matsudaira was born in Tokyo to a shipowner on 5 February 1903. He first went to high school and then studied law at Tokyo Imperial University in his hometown. Although he entered the foreign service in 1926, he did not receive a degree until a year later. His further studies were in Paris, where he got a Doctor of Law. That same year, he also went to Institut d'études politiques de Paris, where he got a diploma.