Hirosuke (広助) was a principal smith of the Shimada school, a lineage of swordsmiths that flourished in Suruga Province from the mid-Muromachi period into the shinto era. According to genealogical records, the school was founded by Yoshisuke, who took the Buddhist name Keizen around the Kosho era (1455–1457). Hirosuke is recorded as a son of the second-generation Yoshisuke, and together with Yoshisuke and Sukemune he is regarded as one of the three representative craftsmen of the Shimada group. Several smiths subsequently used the name Hirosuke, extending the line into later periods. A dated katana inscribed Eiroku 2 (1559) and signed "Shimada Hirosuke made this in Koshu" — once held by Hara Mino Nyudo (Toratane), counted among the Twenty-Four Generals of the Takeda — documents the smith's activity in the late Muromachi period.

The technical character of Hirosuke's work reflects the Shimada school's absorption of Soshu-tradition influences through what is termed Koshu-uchi — forging in the Kai Province manner. The jigane is forged in itame-hada with ji-nie present, while the hamon characteristically takes the form of ko-notare mixed with gunome, often incorporating pointed elements and suggestions of choji. Nie is conspicuously strong, with sunagashi and fine kinsuji appearing in the tempered areas. The boshi tends toward depth, sometimes forming ichimai with a deep kaeri. Among the three major Shimada smiths, Hirosuke's output is noted for producing works of the most magnificent and powerful character.

The Shimada school occupies a distinctive position within the broader landscape of late Muromachi swordsmithing, reflecting the confluence of Sue-Soshu and Sue-Seki influences that shaped production in the Suruga and Kai regions during the Sengoku period. Works showing Koshu-uchi characteristics are concentrated in the period from Eiroku through early Tensho (1558–1592), an era of intense martial demand. Hirosuke's blades, with their strong nie, bold tempering, and powerful form, exemplify the robust aesthetic of this school at its zenith. The rarity of collaborative works — such as the joint-signed wakizashi produced with Gensuke — further underscores the individuality of his production within the Shimada tradition.