The Hirata school of tōsōgu craftsmen traces its origins to Hirata Dōnin, commonly known as Hikoshirō, a shippō (cloisonné enamel) artisan who worked in Kyoto during the Momoyama period. His techniques are traditionally said to have been learned from Korea, and he applied this vibrant enameling method to sword fittings at a time when shippō accorded perfectly with contemporary taste. The art form was employed for architectural metal fittings at sites such as Fushimi Castle and the Jurakudai palace complex, attracting great attention as a fresh form of decorative beauty. Around the Keichō era, Dōnin entered the service of Tokugawa Ieyasu, moving from Sunpu to Edo, where the Hirata family subsequently served as official artisans (kakae-kō) to the Tokugawa shogunate for generations. They were granted a residence in Edo and received a stipend of ten persons' rations (jūnin-buchi), with their shippō techniques transmitted as a secret, one-to-one lineage (isshi sōden) down into the Meiji era.

The Hirata school is distinguished by its masterful use of doro-shippō ("mud" cloisonné), a technique characterized by thickly built-up enamel with vivid, translucent colors. Works employ gold-wire inlay (kinsen-zōgan) to outline motifs, which are then filled with cloisonné in brilliant greens, whites, reds, yellows, and blues, creating a distinctive interwoven beauty. Mount Fuji crowned with pure white snow was a favored subject, especially for the first and second generations, often rendered with gold-inlaid rocks at the base symbolizing wealth. Auspicious themes such as pine, bamboo, crane, and tortoise appear frequently, as do floral patterns (karahana), scrolling vines (karakusa), and wave-and-cloud motifs. While the school's signature technique was cloisonné, later generations occasionally worked without enamel, employing gold nanako-ji grounds, silver suemon crests, and sculptural carving (yōbori), demonstrating versatility in technique. The eighth-generation Harunari, who studied under the Yasuda family (also shogunal purveyors), produced refined iron tsuba combining sukidashi-bori relief with shippō rim inlay, exemplifying the school's ability to balance restraint with decorative brilliance.

The Hirata lineage continued unbroken through the Edo period, with successive generations bearing the common name Hikoshirō and maintaining the family's hereditary role as shogunal artisans. Signed works from the first through fourth generations are extremely rare, making authenticated early pieces particularly precious as documentary material. After the advent of the Meiji period, the Hirata family applied their traditional shippō skills to the production of government decorations and orders, including the Order of the Golden Kite (Kinshi Kunshō), thereby extending their technical legacy into the modern era. The school's works are characterized by sumptuous magnificence and a Momoyama flavor that remains vividly present in their most mature examples, embodying both the technical authority and assured mastery (kanroku) of a lineage that gave form to the aesthetic ideals of its age.