Ichikuri Takaharu served as a bushō and retainer of the Ōsaki clan in Dewa Province during the Azuchi-Momoyama period to the early Edo period. Takaharu was the grandson of Ichikuri Hōgyū.
In 1590, Takaharu joined Hōgyū in an uprising against the new lords in their territory. In an event known as the Kasai-Ōsaki Uprising, former retainers of the Kasai and Ōsaki clans protested the dismissal and replacement of these clans with the Kimura clan. Kimura Yoshikiyo and his son, Kimura Kiyohisa, were assigned control of the territory as part of Toyotomi Hideyoshi’s effort to garner control of the northern provinces in a campaign launched in the summer of 1590 known as the Ōshū Retribution (Ōshū shioki). Upon the outbreak of the uprising, Yoshikiyo and Kiyohisa sought refuge in Sanuma Castle in Mutsu Province, and were rescued by Date Masamune. After Masamune was summoned to Kyōto, Takaharu and Hōgyū, together with their followers, took over Sanuma Castle and made a spirited defense against an assault by Masamune. Outnumbered, Hōgyū enabled Takaharu to safely escape and then made a last stand in the castle, perishing at the age of ninety-two.
After Takaharu’s escape, Mogami Yoshiaki, a powerful daimyō in Dewa Province, recognized Takaharu’s bravery by offering him a stipend of 1,000 koku and the role of deputy of Tsurugaoka Castle in Dewa. In 1614, just prior to the Winter Campaign of the Siege of Ōsaka, Takaharu, together with Shimizu Yoshichika (Yoshiaki’s third son), were accused of conspiring with their opponents, and then killed by Niizeki Hisamasa, a retainer of the Mogami and lord of Fujishima Castle in Dewa.