In 1956 when his colleagues who had joined the previous studio at the same time as him, Koreyoshi KURAHARA and Tatsumi KUMASHIRO, moved to the Nikkatsu, Matsuo worked as an assistant director for 'Waga machi' (My hometown) written by Sakunosuke ODA.
（同期の蔵原惟繕、神代辰巳も日活に移籍した）1956年、織田作之助原作の「わが町」の助監督を務めた。