Fukuzumi Toshihiro served as a bushō during the Sengoku period.  Toshihiro was the uncle of Tsutsui Junkei.

Toshihiro was born as the son of Tsutsui Junkō, a sengoku daimyō in Yamato Province and later adopted by the Fukuzumi clan, becoming the designated heir of Fukuzumi Munemoto.

At the Kasuga Grand Shrine, the Fukuzumi clan served as priests known as kokumin while the Tsutsui clan were members of the Inuiwaki group serving in the role of a tone, meaning an official or priest.  The Fukuzumi were based in the Fukuzumi township located on the western side of the central portion of Higashi-Sannai on the Yamato Plateau.  During the Muromachi period, the son of Tsutsui Junkaku (Gorō) and an unnamed son of Tsutsui Shōkaku were adopted by the Fukuzumi clan.

In the sixth month of 1550, after the death from illness of Tsutsui Junshō at the age of twenty-eight, Fukuzumi Munemoto served as the guardian of Junshō’s lineal heir, Tsutsui Junkei.  In this era, the Tsutsui and Miyoshi clans wielded authority in the Kinai and were allies.  In a letter surmised to have been from 1554, Junkei sent reinforcements to Miyoshi Nagayoshi.  In the second month of 1557, Junkei’s uncle, Tsutsui Junsei, strengthened mutual ties with the Miyoshi, holding a celebration with Hatakeyama Takamasa (the military governor of Kawachi) who, similar to the Tsutsui, backed the Miyoshi.

The Tsutsui family was divided with one faction led by Fukuzumi Munemoto respecting the Jimon school of the Tendai sect and warrior monks at the Kōfuku Temple and the other faction, led by Junsei, loyal to their ties to Kawachi.  In the twelfth month, Junkei was expelled from Yamato by the faction led by Munemoto whereupon he entered Iimoriyama Castle, the residence of Yasumi Munefusa, a senior retainer of the Hatakeyama clan.

In the second month of 1558, Junkei and Munefusa entered Nara to worship at the Kasuga Grand Shrine.  In the eleventh month, Junkei became a son-in-law of the Yusa clan, the deputy military governors of Kawachi.  From around this time, Junsei began to serve as the guardian of Junkei.  In the sixth month of 1559, Munemoto entered the priesthood.  In the eighth month, Matsunaga Hisahide, a retainer of Miyoshi Nagayoshi who opposed Munefusa, commenced an invasion of Yamato whereupon Junkei (who lost Tsutsui Castle) and Junsei sought refuge in Tsubaokami Castle.  In the course of this invasion, the Inuiwaki group ruling the Tsutsui and the Chōshōji clan pulled in forces from Hisahide while the Fukuzumi clan also allied with Hisahide.  In the background, it appears that this was a backlash against the Tsutsui clan who sought to expand their power by joining forces with Munefusa.

In the sixth month of 1566, Junkei reclaimed Tsutsui Castle but, on 10/8 of Eiroku 11 (1568), the castle fell again to Matsunaga Hisahide with the backing of Ashikaga Yoshiaki (the fifteenth shōgun of the Muromachi bakufu) and Oda Nobunaga.  In 1569, the Fukuzumi clan was ousted from their place of residence and the confiscated property was granted to a retainer of Hisahide named Yamaguchi Hidekatsu.

In the sixth month of 1571, Junkei wed the adopted daughter of Ashikaga Yoshiaki and, in the eighth month, during the Siege of Tatsuichi Castle, he defeated Matsunaga forces and reclaimed Tsutsui Castle.  In the fifth month of 1576, Nobunaga recognized Junkei’s governance of Yamato.  In the ninth month of 1581, during the Conquest of Iga, the Fukuzumi clan served as the commanders of the Tsutsui clan leading forces to the southern portion of Yamato to capture the area of Nabari.

In the twelfth month of 1583, upon orders of Hashiba Hideyoshi, fiefs were granted to eleven members of the Tsutsui clan and Fukuzumi was included among the recipients.

Thereafter, in the eighth month of 1584, Junkei died.  Junkei was succeeded by an adopted son, Tsutsui Sadatsugu but, in the eighth month of 1585, Sadatsugu was transferred to Iga Province and removed from his position in 1608.  In 1615, at the Winter Campaign of the Siege of Ōsaka, Toshihiro was accused along with his lineal heir, Tsutsui Juntei, of colluding with the Toyotomi family and both of them were forced to take their own lives.

Toshihiro’s second son, Tsutsui Junsai, was also adopted by Junkei.  He had landholdings of 5,000 koku in Fukuzumi in Yamato.  In 1615, during the Summer Campaign of the Siege of Ōsaka, Junsai’s son, Tsutsui Masatsugu, failed in his bid to defend Kōriyama Castle from an attack led by Ōno Harufusa and took his own life.  This is known as the Siege of Kōriyama Castle.  Masatsugu was succeeded by his son, Tsutsui Masanobu and although he lost his fief in Yamato, he later served as a hatamoto, or direct retainer of the bakufu.

Later descendants

In 1855, toward the end of the Edo period, a descendant of the Tsutsui family named Tsutsui Masanori participated in negotiations for a peace treaty with the Russian Empire.