The reading of the characters of his name was originally "Takenobu"; however, with the birth of the first son of the Shongun Ieyoshi TOKUGAWA in 1813, whose name was Takechiyo, having a sylable with the same pronunciation of "Take"was deemed to be inappropriate, and was therefore changed to "Osanobu".
もともと、養信の読みは「たけのぶ」であったが、文化(元号)10年（1813年）、将軍徳川家慶に長男竹千代が生まれると、「たけ」の音が同じで失礼だとして「おさのぶ」によみ改めた。