When Ujiteru suddenly died in 1536, Yoshimoto came to be involved in the family succession dispute with Etan GENKO, Yoshimoto's older paternal half-brother who was also in the priesthood, and Yoshimoto, who finally won the dispute due to Sessai's intensive efforts, quit the priesthood and took over the position of the ninth family head of Imagawa clan as well as the shugo in Suruga Province, and began calling himself Yoshimoto (Hanakura Rebellion).
天文(元号)5年（1536年）、氏輝が急死したために駿河に戻り異母兄で同じく出家していた玄広恵探との間で家督争いとなるが、雪斎の尽力で勝利し、還俗して今川氏第9代当主・駿河守護となり、義元と称した（花倉の乱）。