(Japanese: “family name”), hereditary title that denoted the duty and social rank of an individual within the Japanese sociopolitical structure from the late 5th to the late 7th century. Titles, or kabane, included the categories omi, muraji, tomo no miyatsuko, and kuni no miyatsuko.

The imperial Japanese Yamato line arose as the most powerful members of this kabane system, although during the 6th century AD, a number of leaders, especially those possessing the high ranks of omi and muraji, overshadowed the Yamato rulers, causing many of them to become no more than figurehead sovereigns.

One of the first acts of the Taika reform (Taika era reforms), which reasserted imperial rule in AD 645, was the abolition of the kabane system. In 684 a system of eight noble ranks, assigned by the emperor, was instituted in its stead. The most important of these new titles were granted to friends or loyal supporters of the emperor.

The Japanese use of kabane probably derived from the similar Korean bone-rank system.