Yoshinobu was the third son of Nakajima Shingobei, known by the common name Yashichibei. He became the adopted son-in-law of the first-generation , and his descendants include the brothers Masahiro (first generation) and Yukihiro (first generation). Tradition holds that he died in 'ei 10 (1633), though extant works dated 'ei 13 (1636) and surviving correspondence addressed to him from 'ei 14 (1637) prove this reported year of death to be erroneous. He is thought to have served in a supporting capacity to the first-generation , and surviving examples of his work are few.
Yoshinobu's forging is a tightly packed with finely adhering in -like particles and delicate . His is characteristically a high, flamboyantly varied centered on , with abundant and , deep , and well-attached . The valleys of the irregular temper display an especially concentrated formation. Throughout, runs with and occasional , producing a bright . His in are notably wide with thick , sometimes employing , and several bear including , , and . The tang finishing with and the manner of his signature closely resemble the presentation signatures of the first-generation Tadahiro and the early signatures of his own son Masahiro.
The regards Yoshinobu's work as "a pioneering example of the style later broadly termed Soba-," noting the pronounced variation in the produced by large-scale patterning and especially brilliant irregular tempering. The affinity between parent and child workmanship, observed in shared construction methods and carving styles with the first-generation Masahiro, offers what the calls "an intriguing view into the commonality of parent-and-child workmanship." Among Yoshinobu's very small body of surviving work, the designated pieces are recognized as particularly superior in quality and precious as documentary material for researching the scope and characteristics of his art.