Hiroyasu was a smith of the lineage of Province, traditionally said to have been the son of Yukihiro. He emerged in the early period alongside such peers as Yasuyoshi, Yukihiro, Yoshisada, Kunihiro, Hiroyuki, and Sadayoshi, all of whom inherited their master's manner and were notably active. The school broke decisively from the older, classical style of Kyushu workmanship that had previously prevailed, establishing a refined approach in which both and are bright and clear, with an uncluttered, sophisticated character incorporating and . Among extant works, there is an example dated Shohei 20 (1365), and in the a piece dated Shohei 13 (1358), allowing his approximate working period to be understood. Surviving signed works are limited to and small , making documentary material by this smith particularly precious.
Hiroyasu's forging is characteristically mixed with and areas of large , with the grain standing out prominently. Thick adheres, and fine enter densely and vigorously, imparting a powerful quality to the steel, which often carries a somewhat dark, blackish tone. A faint appears in many examples. The is typically a or basis mixed with , , and elements with a pointed tendency, accompanied by and . The is thickly applied, with slight unevenness in places, and the temper line is enriched by , , and throughout. The shows a characteristic -- a subdued tendency -- that distinguishes his work within the group. In the upper portions of certain blades, -like patches of appear intermittently, creating an archaic flavor. The typically runs in with a pointed tendency at the tip, turning back in , and showing vigorous -- a feature consistently noted across his attributed works.
Compared with other smiths of the group, it is difficult to identify a particularly striking individuality in Hiroyasu's work; however, among blades appraised as belonging to the lineage, pieces in which is especially conspicuous are frequently encountered, and this prominence of is the quality most consistently cited in support of attributions to his hand. The repeatedly observes that his forging -- thickly covered with and richly animated by -- possesses a powerful quality, and that together with the imposing -period , his works convey a palpable sense of vigor and spirited force. Several designated examples are described as transmissions from distinguished collections, including the Kuroda, Hisamatsu, and Takasu Matsudaira families, and are accompanied by attesting to their longstanding recognition. Within the tradition, Hiroyasu occupies the position of a smith whose technical refinement fully embodies the bright, clear, and forceful manner of the school, and whose finest attributed works are praised as superior pieces brimming with spirit.