The Kusakari school (草苅) was one of several distinguished kinko lineages retained as official domain craftsmen (kakae-ko) by the Date family of Sendai, one of the great han of Mutsu Province. Alongside the Shibuya, Oguma, Saito, Masamura, and Sukegawa houses, the Kusakari artisans served as han-ko to the Date throughout the middle and late period. As the consistently note, "it was particularly through the hands of the Shibuya and Kusakari families that the technique of flat inlay (-) developed and won widespread acclaim." The founding master, Kiyosada (清定, first generation), used Kusakariya as his house name. He apprenticed under Masamura Shichiemon, a craftsman in service to the Sendai domain, then travelled to to study under the Omori family before returning to Sendai during the Tenmei era (1781-1789) to assume his position as domain artisan to the Date house.
The Kusakari school's collective style is defined by a highly distinctive inlay method practiced on grounds. The canonical technique, described with near-formulaic consistency across the corpus, proceeds as follows: on an (stone-textured) ground, the outlines of the design are carved in high relief and inlaid with gold wire (kinsen-); the interior is then polished out () to lie nearly level with the ground plane, and filled with geometric patterns executed in -. The repertoire of interior patterns is itself a hallmark: kikko (tortoiseshell), (linked swastika fret), masugata (square diaper), asanoha (hemp leaf), (woven mat), shippo-tsunagi (linked seven-jewel), nami-chidori (waves with plovers), and soryu (paired dragons) recur across nearly every designated work. The signature subject is the gunbai (war fan), with multiple fans arranged on front and reverse, each rendered with a different interior pattern — the note that "nearly every gunbai is rendered with its design altered in detail one by one." The standard ground is , though at least one rare example employs , suggesting a specially commissioned piece of exceptional care. Gold rims, sometimes bearing flowing-water (ryusui) designs, and gold-lined complete the refined presentation.
The Kusakari school's significance rests in its mastery of a technically demanding inlay method that became synonymous with Sendai kinko craftsmanship. Kiyosada's works are praised across the for their "splendid command of technique" and the "strong professional pride" they convey, with designated examples ranging from characteristic gunbai to rarer departures such as a raptor-and-cypress composition that combines and with the school's signature inlay manner. The consistency of the 's assessments — describing the works as displaying "the maker's distinctive character together with his accurate and advanced technical skill" — affirms the Kusakari tradition as a defining expression of domain metalwork in the service of one of -period Japan's most powerful houses.