Kunisada (国定) is traditionally identified as a disciple of Kuninobu of the Yamashiro school, and it is transmitted that around the Bun'ei era (1264–1275) he relocated to Tanba Province. His workmanship continues the tradition, and his blades at first glance possess what the describes as "the dignified quality characteristic of Kyo work." A separate line of attribution links the name to the school under the reading Kunisada, recorded in sword catalogs as a student of Kunitoshi, though the relationship between the two lineages remains a subject for further research.
In his -line , the forging shows with plentiful , and the temper is fundamentally mixed with small , into which and enter strongly. A recurring feature across these works is a feeling of nijubba — a doubled or layered effect in the hardened edge — intermingled within the temper pattern. One displays a -like intent recalling Ayakoji Sadatoshi together with a pronounced jubba tendency. Works attributed to the school line show a markedly different character: with thin and wide in proportions, well-forged with , and a of with intermixed that becomes in the upper half — characteristics described as typical of period workmanship and comparable in style to Hasebe Kunishige.
The 's assessments emphasize the continuity of school aesthetics in the attributed to this smith, noting in particular the dignified quality of Kyoto tradition forging and the distinctive nijubba character of the temper. The presence of works in the Imperial Household collection and transmission through the Tayasu Tokugawa family attests to the historical esteem in which blades bearing this name have been held. Published references include the Kozan , Kanto Zuiroku, and Kusanagi no Ya .