On the first day of the third month of 763, Oi was promoted from Shorokuinojo (Senior Sixth Rank, Upper Grade) to Ge-jugoinoge (Jugoinoge (Junior Fifth Rank, Lower Grade) given to persons outside Kyoto), and was appointed Shusen no kami (Director of the Ministry of Ships).
天平宝字7年（763年）1月9日、子老は正六位上から外従五位下に進み、主船正に任じられた。