Shibukawa Yoshitaka served as a bushō during the Sengoku period.  He was the lord of Hichiyama Castle in Bingo Province.  He held territory in the Mitsugi-Hachiman area and the Sannan locality in the Numakuma District of Bingo.

He adopted the monk’s name of Hōunken.

Initially, he established his main base at Katsuyama Castle.  In 1526, he built Hichiyama Castle in his territory on the land of a branch of the Mitsugi-Hachiman Shrine.  Thereafter, this became the residence of the Mitsugi-Shibukawa clan.

Yoshitaka received his formal wife from the Miya clan, the most powerful kokujin, or provincial landowners, in Bingo Province and former military governor of Bitchū Province.  Members of the Miya clan had close ties with the Ashikaga clan who served in the hōkōshū, the military organ of the Muromachi bakufu.

To further solidify his base of power, Yoshitaka maintained friendly relations with the Kobayakawa clan, powerful kokujin as members of the hōkōshū with landholdings in Aki and Bingo provinces.  Prior to 1507, he transferred a portion of his landholdings in Mitsugi to Kobayakawa Sukehira.  Later, after incurring an attack by the Amago clan, Yoshitaka received reinforcements from the Kobayakawa clan.

His son, Shibukawa Yoshimasa, wed as his formal wife the daughter of Mōri Hiromoto, a kokujin in Aki Province.

For generations, the Shibukawa clan held disparate landholdings across several provinces including the land of the Daikōmyō Temple in Kyōto.  Nevertheless, the clan was known to struggle with respect to the management of their landholdings.