Kuwayama Shigeharu served as a bushō and daimyō during the Azuchi-Momoyama and early Edo periods.  He was the first head of the Kuwayama family in the Yamato-Shinjō domain in the Edo period and served as the lord of Takeda Castle in Tajima Province and, later, as the head of the Izumi-Tanagawa domain.  Shigeharu held the titles of Junior Fifth Rank (Lower) and Master of the Office of Palace Repairs.  He learned the tea ceremony from Sen no Rikyū based in Sakai.

In 1524, Shigeharu was born as the son of Kuwayama Mochinori in Kuwayama-no-shō in the Kaitō District of Owari Province.  The Kuwayama family were descendants of Yūki Tomomitsu, a powerful retainer of the Kamakura bakufu.

Shigeharu served as a yoriki, or security officer, for Niwa Nagahide, a senior retainer of Oda Nobunaga.  He participated in the Battle of Anegawa and was praised by Hashiba Hideyoshi for his calm demeanor in battle.  In 1574, upon request of Hideyoshi, Shigeharu transferred from the Niwa to the Hashiba family.  In 1580, he became the lord of Takeda Castle in Tajima Province with a fief of 10,000 koku.

In 1583, at the Battle of Shizugatake, he fought valiantly to thwart an attack led by Sakuma Morimasa against Shizugatake fortress.  Shigeharu was recognized for his contributions, increasing his fief to 20,000 koku.

In 1585, after the conquest of Kishū, when Hideyoshi’s younger brother, Hashiba Hidenaga, became the lord of Kii Province, in the fifth month of the same year, Hideyoshi appointed Shigeharu at Ōsaka Castle to serve as the chief retainer of Hidenaga.  His fief increased to 30,000 koku and he became the chamberlain of Wakayama Castle.

On 7/8 of Bunroku 4 (1595), when Toyotomi Hidetsugu went to Fushimi Castle in an effort to vindicate himself of suspicions that he was plotting a rebellion, Shigeharu was assigned to guard the main gate to the castle.  For this work, his fief was further increased to 40,000 koku in Tanagawa in the Hine District of Izumi Province.

In 1596, he entered the priesthood, adopting the name of Kuwayama Jibukyō-Hōin.  On 5/11, he transferred his position of Master of the Office of Palace Repairs to his lineal grandson, Kuwayama Kazuharu, and granted a fief of 20,000 koku to Kazuharu and 10,000 koku to his second son, Kuwayama Motoharu.  Henceforth, Shigeharu managed the remaining fief of 10,000 koku.

In 1600, after the Battle of Sekigahara, Shigeharu received 4,000 koku from Kazuharu, and 2,000 koku from Motoharu, so his fief rose to 16,000 koku in total.

Shigeharu died on 10/1 of Keichō 11 (1606) at the age of eighty-three.  Among his landholdings in Tanagawa, his second son, Kuwayama Motoharu, inherited 6,000 koku and his son, Kuwayama Kiyoharu (Shigeharu’s grandson), inherited 10,000 koku.