In 1491, joining his lord, Yoshihiro SHIBA, Owari no kuni shugo (provincial constable of Owari Province), Toshinobu went on an expedition to Sakamoto in Omi Province (Otsu City) to conquer Takayori ROKKAKU (Chokyo-Entoku Wars) together with Toshisada ODA of 'the Oda Yamato no kami family' who is said to be his father.
延徳3年（1491年）、六角高頼征伐のため、敏信は父とされる「織田大和守家」織田敏定と共に近江国坂本(大津市)へ主君・尾張国守護の斯波義寛へ従軍したという（長享・延徳の乱）。