Takeda Mitsukazu served as a bushō during the Sengoku period.  He was the head of the Aki-Takeda clan.  He also had the name of Mitsusada and the pseudonym of Tarō.

Mitsukazu was born as the eldest son of Takeda Motoshige in Aki Province.  His formal wife was the daughter of Kumagai Motonao.   He held the titles of Assistant Vice Minister of Justice and Governor of Aki.  It is surmised that he received one of the characters from the name of Takeda Motomitsu, the natural father of Takeda Nobuzane, after receiving Nobuzane from the Wakasa-Takeda clan to become the next head of the Aki-Takeda clan.

On 10/28 of Eishō 14 (1517), at the Battle of Arita-Nakaide, Mitsukazu’s father was killed in action whereupon Mitsukazu succeeded him as the head of the Aki-Takeda clan.  In that same battle, however, senior retainers including Kumagai Motonao and Kagawa Yukikage were also killed; and, several years prior, Nobunao’s father, Kumagai Yoshinao died.  Having lost a number of hereditary senior retainers all at once, from the point forward, the Aki-Takeda clan fell into decline.  Similar to his father, Mitsukatsu excelled in the military arts, exceeding the his lords, the Amago clan, in battle against the Ōuchi and Mōri clans.  Nevertheless, he could not recover the power attained in the era of his father.

In 1524, Ōuchi Yoshioki and Ōuchi Yoshitaka (father and son) led an army of 30,000 soldiers and laid siege to Mitsukazu’s base at Satō-Kanayama Castle.  Upon hearing this new, Amago Tsunehisa rushed to Aki in an effort to support Kanayama Castle and ordered the deployment of the kokujin under the command of the Amago in Aki.  Owing to the support of the Amago army, the defenders held the castle and the Ōuchi army withdrew in an event known as the First Siege of Satō-Kanayama Castle.  There is a legend that Mitsukazu wielded extraordinary strength and during this battle fought on the front lines alongside his soldiers to defend the castle.

Mitsukazu remained active, intervening in the succession struggle for the next head priest of the Itsukushima Shrine, supporting Tomoda Kōzuke-no-suke who opposed the Ōuchi clan.  He could not, however, stem the decline of the Aki-Takeda.  Differences over landholdings, among other issues, spurred Kumagai Nobunao to separate from the Aki-Takeda, dealing a fatal blow to the prospects of the clan.  Meanwhile, Mitsukazu had poor relations with his formal wife who was the younger sister of Nobunao, and their divorce may also have been a factor in the alienation of Nobunao.  In the eighth month of 1533, Mitsukazu attacked Nobunao’s base at Miiri-Takamatsu Castle, but withdrew owing to a stiff defense.

On 6/9 of Tenbun 9 (1540), while continuing efforts to eliminate Nobunao, Mitsukazu suddenly died at the age of thirty-seven with no heir.  He did have natural children, but they were illegitimate and, with the exception of Takeda Kosaburō (Sōkei), died prematurely.  As a result, he received Takeda Nobuzane from the Wakasa-Takeda clan of the same family, but, by this time, the fate of the Aki-Takeda clan had been sealed.

The family temple of the Aki-Takeda clan was at the Fudai Temple, a sub-temple of the Ankoku Temple in Aki.  There is a grave there for Takeda Gyōbu-Shōyū (Mitsukazu’s title).  His illegitimate son, Kosaburō, adopted the surname of the Suō-Takeda clan and served the Mōri, but there is also a grave for Mitsukazu at the site of the residence of the Suō-Genji Takeda family.  This is said to have been the grave and remains brought from a location near Satō-Kanayama Castle.